My Little Pony: Friendship Is Magic/WMG/Secondary Characters

Guesses about the Secondary Cast, Like Spike and the Cutie Mark Crusaders. If you have a guess about something else, then

"Meta Guesses go here

Setting Guesses go here

Mane Character Guesses go here

BUT Pinkie Pie Guesses go here

Royalty Guesses go here

Minor Character Guesses go here

Future Stories go here

Jossed Guesses go here

Confirmed Guesses go here"

"and you can still go back to the Main WMG Page, here"

Spike will outlive the Mane Cast and all of the other ponies.
I believe that Word of God said that Fluttershy is 22, and assuming the rest of the main six are the same age (even Pinkie, she had a birthday), Twilight has to have been born in 1989-1990. (also assuming that the series takes place in present times) In The Cutie Mark Chronicles, Twilight looks to be about the CMC's age, which is probably around 11, making The Cutie Mark Chronicles takes place in about 2001. As You Know, in the Cutie Mark Chronicles, Spike's egg hatches, which would put Spike at around 11 years old., yet he's still considered a baby. Which leads me to believe that 1 dragon year = 10-11 pony years. Again, assuming ponies live to be as old as humans, there is extremely slim-to-none chances that the Mane Cast and everypony else will even survive to watch Spike turn "seven". Also doubles as a Tear Jerker.
 * This is kind of a give. Dragons are already known to have much longer lifespans than ponies.
 * Link to the Word of God? All I honestly remember is her saying the Mane cast are young adults, whose mentality fluctuates around 12-22, as necessary for the plot. Other than that, while Dragons are long lived, ponies in this setting are shown to be very long lived too: Granny Smith is established as being over 100 years old.
 * Where was a number age for Granny Smith given? She helped found Ponyville generations ago, but that isn't a number, and has some consistency issues.
 * In "Dragonshy," it was mentioned that dragons can sleep for as long as a century at a time. Incidentally, while Spike is called a baby dragon, the show establishes that it's more a reference to size than his age or his place in the dragon life cycle, about which practically nothing is known. He certainly isn't considered an infant by anyone.

Spike is just a normal, run-of-the-mill dragon with normal fire.
It's not that his breath has special letter sending powers, the scrolls themselves are made to be sent to various places when set on fire. This is why Twilight's book was turned to ash in Owl's Well That Ends Well instead of just being sent to Celestia. As for the green coloring, Spike's diet is probably unusual due to not being wild. If I had to guess, he eats a lot of copper coins [them being cheaper than gems] and nibbles on rocks if he needs a snask. Copper sulfide would make green fire in our world.
 * I've got it! When scrolls are addressed to somepony and then set on fire, they're sent in the most convenient way for the receiving pony to get it - for Celestia it's her little alcove thing we see at the end of Griffon the Brush Off (not to mention she gets bobarded from above with the scrolls Spike accidental sends), and for Twilight the letters are received through Spike!

Spike does not look like a normal dragon because of Twilight.
Twilight did know how to hatch an egg, but simply did not have enough brute force at the time. She did not, however, know what a dragon hatchling looked like, and when she did have enough brute force, she just enlarged the embryo form instead.
 * During Twlight's test there is a poster stuck to the side of the table holding Spike's egg, and the picture on it is of a dragon which could reasonably be - spikes, lack of wings - a older example of whatever Spike's breed is. If we had seen the judges' reaction to Spike, that might have told us what they were expecting and whether he looks the way he should.

Spike is a stealth Audience Surrogate.
Expanding on the fridge entry regarding the Gala and Spike's response (he claims not to enjoy such "frilly, frou frou nonsense", yet giggles excitedly when the others are out of earshot), Spike's personality resembles a typical male viewer of the show. He snarks about the characters, doesn't want to be involved in fashion or other girly stuff, and all around feels out of place. Yet it's clear that he has a lot of fun as a whole, and wouldn't have anything any other way.
 * On the other hand his reaction may stem from the fact that just because he doesn't want to go to the Gala doesn't mean he doesn't want to be invited. His reaction to the gala is pretty much that of a littler brother having to hear about his sister's upcoming slumber party, sure he might not want to be there for the whole thing, but that doesn't mean he wants to be totally excluded either. The rest of this is a dead-on description of the male Periphery Demographic though.

Spike is a young Eternal Dragon
Because why not?
 * It's possible he may grow up to be an eastern-styled dragon given his lack of wings and affinity for mustaches.
 * In "Party of One" it looks like Spike is able to fly (or at least float or levitate) even though he doesn't have wings, another thing usually associated with eastern dragons.

Spike's species imprint on the first living thing they see when they hatch.
In Spike's case, it's possible that he's imprinted onto unicorns, such as his closest friend, Twilight. Hence why he also has a near-obsessive crush on Rarity (another unicorn). He's been wired to see unicorns as potential mates.
 * Also, it could be assumed that the first living thing Spike saw was either Twilight or Celestia. Twilight may even be more probable since Celestia is a Unicorn Pegasus.
 * As of "Cutie Mark Chronicles", we get confirmation that Twilight probably was the first creature Spike saw - hell, she was the one who hatched him!

Spike is somehow related to Spyro the Dragon.
Ancient ancestor maybe? With the events of the spyro games taking place long after the ponies too, have been wiped out as the humans were before them?

Spike isn't "Spike's" real name.
Dragons never reveal their Truename. So Spike is a nickname of sorts. If anyone does know his real name, Twilight might.

Spike is half pony.
His head is slightly pony-like, he's the only dragon we've seen with differently colored scales and spikes (like a mane), and he has a crush on a pony.
 * Maybe his mom was a naturalist who was studying dragons during mating season and she got too close.
 * He may be like a dog; his breed was domesticated/brefriended by ponies, and so they're tamer. He also doesn't look much like a full-grown dragon. At all.
 * Jossed. "Secret of My Excess" shows that Spike, at least when he's fully grown, is just like the other two dragons we've seen. Just with a couple of birth defects, or possibly of a different, wingless and differently colored race.
 * In "Dragon Quest" the teenage dragons accuse Spike of being part pony. Granted they're also Jerkass teens.

Spike's mom is Twilight
She gave one of her ovum to Celestia who impregnated it with dragon seed and gave the egg to Twilight. Explains why he's purple.

Spike will be given a male pony friend.
Who he refers to as his "brony."

Spike is a hybrid dragon.
In the show, we see few different types of dragon species, and it wouldn't be too unreasonable to believe there are a few other different species as well. Spike is a crossbreed between two different dragon species, a huge taboo in the dragon world. Either his egg was abandoned and then picked up by Celestia, or his parents gave him to her so he can grow up in a safe, accepting environment. Had he stayed living with dragons, he would've been tormented constantly for being a hybrid, or perhaps even killed for it.

Spike will not grow up to be like the dragons we have seen..
Instead he will grow up to be a dragonborn. Proof for this theory? His day dream in "Dog and Pony Show", why would he imagine all that armor and stuff if he knew he would grow up to be a normal dragon, wouldn't he have just imagined himself as a dragon destroying the Diamond Dogs? As for the sudden growth in Twilight's flashback, that is just what happens when the embodiment of Magic unleashes her power. Unless of course, ponies turn into plants when they grow old. This also makes Spike/Rarity a lot easier....
 * Agreed that baby!Spike growing gigantic in 'Cutie Mark Chronicles' was Twilight's magic going haywire and not showing us what he will look like. Even if he doesn't end up like his Imagine Spot in 'Dog And Pony Show' his appearance suggests he won't look like either the cave-dwelling dragons he's met/been attacked by, or the one in the river.
 * Jossed. In season two episode "Secret of my Excess" Spike's hoarding instinct triggers and he goes into what amounts to dragon puberty; over the course of a couple of days he gets about as big as that Ursa Minor.

Spike has serious species identity issues from being raised among ponies.
He has a crush on a pony, and in his imagine spot, he rescues Rarity as a KNIGHT, a dragon's natural enemy.
 * Largely agreed. However, ponies are the only people (for want of a better word) he's ever been around, and it's not hard to imagine a young chap like Spike getting a crush on a pretty lady like Rarity. And as for the knight part, he's probably cottoned onto the fact that Rarity quite likes the idea of having someone dashing, brave, etc, taking an interest in her. So, Spike's Imagine Spot fills in his 'princess' rescue fantasy accordingly.

Rarity is not Spike's first cross-species crush.
In episode one, Spike was seen carrying a present. When Twilight asked him what it was, he says it was a present for Moon Dancer. A few minutes before, an unnamed pony invites Twilight to a party Moon Dancer was throwing in the palace courtyard. Assuming that renting the palace courtyard isn't something just anypony can do, along with how quickly Spike falls for Rarity, it could imply that Moon Dancer was a noble, and Spike just has a thing for regal ponies (possibly a subconscious reaction because of their access to jewels).
 * Alternatively, Where da White Ponies at?

Spike comes from a far away place where dragons are hunted.
In this place, dragons are feared and hated. Often they are killed on sight, and while strong, they are too few in numbers to fight back for the long run. Princess Celestia takes in refugees and eggs smuggled into Equestria, but since the journey is long and dangerous and since everyone in that land is out to kill dragons, very few actually make it. Spike's egg was smuggled in by a benevolent pony after all his relatives were killed, which is why he's being raised by ponies.

Spike being raised by ponies because of a pact between The Dragons and Princess Celestia
Sort of like how Highfather and Darkseid switched sons to prevent war between them.

Hoity Toity and Spike are friends.
Hoity Toity watched Rarity's fashion shows as a favor to Spike.

Spike is the King of Dragons.
His egg was given to Princess Celetia for safekeeping. As seen in the previous WMG his egg was never supposed to hatch (dragon's eggs will hatch naturally in their own time, but it takes several years). Spike was essentially born premature. He was eventually passed to Twilight Sparkle because of her great knowledge and the care she took in her studies reflected the level of care she also put into raising Spike. Spike is being groomed to move the Dragons away from their solitary lifestyle and to a more centralized form of government with greater socialization and less fighting amongst one another. Notice that Spike doesn't seem to regard Princess Celestia with much more respect than he would any other Pony and he is one of the few (only?) characters who is shown not bowing to her, this is because he is not one of her subjects, but her equal.

Spike was born from a fake egg.
Going with Unwinnable Training Simulation based WMG in the Twilight Sparkle folder on the Mane Characters page. The egg in Twilight's entrance exam was fake, but Twilight turned it real with magic. Making this an Achievement In Ignorance.

Spike's singing voice is ridiculously sexy.
He's the only Mane character who hasn't sung yet (well, except in "Equestria Girls", but that doesn't really count), one of his episodes will revolve around how he has a really good singing voice (dubbed by a guy). Possibly in a Whole-Plot Reference to the story of the Nightingale.
 * Even if it does count.
 * Funny I should read this part after I watched this video.
 * Funny, I was thinking of this one.

Spike is some kind of special breed Astropath Dragon
Consider this: Spike is visually slightly different from other dragons we've witnessed, he breaths wierd green fire and can send communiques across great distances magically. Perhaps he's a special breed either engineered by Celestia or one that came about by some bizare fluke that's specialised into an organic magical telegraph system alá the Astropaths. This may also explain why his egg was present at Twilight's entry exam, since the ponies use the species, and possibly they need magic to be able to use the messaging talent.

Spike will grow wings.
The other dragons we see in the series (excluding Steven Magnet) resemble Spike in many ways, such as the spade tail, the ears/fins on the head, and of course, the spikes that get larger on the head. The only thing that seperates them is the wings. Spike will go through a growth spurt where he grows wings and he needs help learning to fly. He's initially clumsy and this makes him feel embarassed, akward, and ashamed so he runs away. But the Mane Cast finds him and they tell him they still love him and they'll help him fly. The lesson will be that friends help each other through hard times.
 * This could also lead to more screen time for Scootaloo, since she hasn't learned to fly either.
 * It could be that culturally speaking getting their wings is the dragon's equivalent of getting their cutie mark, Spike may go through an episode wondering why he hasn't gotten his yet.
 * Would love Spike to get wings (because yay, dragons!) but if it's said that the CMC are unlikely to get their cutie marks because the makers want the episodes to be viewed in any order then wouldn't the same go for giving Spike such a radical design change?
 * It doesn't seem like he will be getting wings both times he is shown as an adult dragon he is wingless, unless the thing about getting wings is the equivalent of getting a cutie mark is true...

Spike absorbed some of Discord's power while 'borrowing' an Element of Harmony.
Because in the episode immediately subsequent, he's a bit more aware of the fourth wall than usual,.

Spike is the same type of dragon as Steven Magnet.
There the only two dragons shown without wings.

Spike will be given a Henshin Hero transformation.
In keeping with the Mane Cast's Magical Girl transformations.

Spike's magic fax-machine ability isn't natural to his breed of dragon.
Rather, its a side-effect of the massive overload of magic Twilight used to hatch him and transform him by accident.
 * Or he's been magic'd by Princess Celestia.

Spike is a prehistoric dragon.
His cute little purple-and-green egg wasn't fake: it was a fossil. To revive him, Twilight Sparkle unconsciously used the ancient amniomorphic spell- a spell that the mighty Star Swirl himself invented. Effectively, this makes Spike the Last of His Kind.

Spike will be granted his own special Cutie Mark.
After an episode where he feels ostracized and left out because Dragons don't have cutie marks. Either Twilight or Celestia will use their magic to grant him one of his own after proving himself in some fashion. Ideas for his mark are:
 * A burst of green fire
 * A scroll in engulfed in green flames
 * a stylized green dragon
 * A dragon's wing
 * A microphone (he does love announcing…)

Spike will gain at least one New Super Power.
The Meet Spike the Dragon video, released on September 22, 2011, mentions that Spike is "still discovering his dragon powers." Perhaps this will happen in one or more upcoming episodes.
 * Well, he finds a way to set off a growth spurt, which is kind of a super power...

Spike will have a bigger role in Season 2 than he did in season 1.
As the only male member of the main cast, and the one who had the least face time in the first season, there's definitely room for him to have more spotlight.

Spike's Age
Expanding on the WMG about The Mane Six. Spike doesn't age like a pony but I would guess that his mental age is around that of a 13-15 year old, given that he basically went through puberty in "Secret of My Excess" and is visably more mature then the CMC and not that much younger than Twilight.

Spike will never grow up.
It seems that from "Secret of My Excess", the size of a dragon's greed and hoard completely determine how old a dragon gets. And since Spike will not hoard again…
 * He probably will, eventually, but it will most likely take a very long time without sudden greed.
 * Agreed. Question is, then, how much a dragon ages without the effect of greed and hoarding. Spike's not the little baby he was in Cutie Mark Chronicles, and it could be intentional that his character design has changed somewhat over time (he does look less…chubby).
 * Was that change in size from growing over time, or from developing a stronger personality, including more of a desire for things?

Spike isn't a flying dragon, he's a magic dragon.
Check it out! He doesn't have wings, didn't grow any during his greed-fueled premature maturity, and doesn't even see himself as getting wings in adulthood (in his rescue Rarity fantasy against the Diamond Dogs). Twilight Sparkle got him in a magic school (where a familiar who can someday learn magic would be helpful), so although there isn't any really solid proof, I'm calling it.
 * He might still fly someday, if he learns the right spells for it.

Spike's parents...
Are Spyro and Cynder.

Spike's adult form will appear again at some point, but in a completely different fashion
Either he somehow gains the ability to transform into it (not at will, but if certain circumstances are met) or the group will face a threat, possibly the next Big Bad, that forces them over the Godzilla Threshold and Spike willingly invokes it to save the day, the group having to talk him down afterwards.
 * Alternatively, Spike ATTEMPTS to invoke this growth spurt again to try to help them, but can't because there's no greed in his heart, only a desire to protect the ones he loves. But this will result in him taking on a third, different adult form born from the Power of Love and Power of Friendship it may or may not also involve the Elements of Harmony empowering him.

Spike's crush on Rarity is still just a "crush" and won't really grow into anything more.
While it's been revealed that Rarity herself knows about Spike's "romantic" feelings for her. I have my doubts that it'll evolve into an actual relationship for a number of reasons, mainly the ones of Spike being a youngster and a different species, but also because Rarity would prefer their relationship to be the way it always was. Which wuld fit right in with a cartoon about friendship aimed primarily at children.
 * Alternatively: Rarity will bide her time and use this as a chance to both test Spike's feelings for her to make sure they're more than just a crush and mold him into the perfect gentleman. If she can then get him to grow to a manageable size, she'll have the perfect boyfriend. Well, aside from him being a dragon and her being a pony.

Spike can assume his giant dragon form at will, just with the intellect and self control he has now.
Much like Luna can turn into Nightmare Moon at will, but not be evil. I say this because…well, why the hay not?

Adding on to that...

Spike isn't really a baby dragon; He's in Sleep Mode Size.
Spike is able to reach adult size in twenty-four hours or less with the proper stimuli, suggesting that he's reached the chronological point of dragon adulthood. Additionally, he didn't have to eat anything to fuel the majority of that growth. The other dragons stay in their larger forms all the time because they don't have friends to remind them of stuff other than greed, or give them a reason to assume the smaller, more vulnerable size.

Spike's 'greedy' adult self wasn't his 'natural' adult form.
The more angular, 'cool' version of Adult!Spike is an alternate adult form. The 'cuter' form we saw when Twilight accidentally aged him after hatching is the form resulting from natural aging, and is rarer than the greedy form due to the high willpower required to reject the hoarding instinct.
 * Spike has a form that looks a lot like the one from Cutie Mark Chronicles for a moment, while he was destroying Sugarcube Corner. That seems to imply that Twilight didn't quite turn him all the way into an adult.
 * One theory is that rather than his greed causing his maturation it was actually his maturation that caused his greed. For a dragon in the wild there are more rivals and stiffer competition than Spike faces in Ponyville. After one day he was already bigger and stronger than almost anyone else in town and could just take whatever he wanted. After that it all just snowballed and caused his extremely rapid growth and monstrous appearance. Greed is a natural thing for Dragons, it helps them survive since they can eat almost anything, require large amounts of food, and tend to use their hoard as an emergency food supply. Kind of like how a boy starting puberty gets a shot of testosterone and can cause a jump in aggressive tendencies that can become destructive if not properly cared for.

One of Twilight's duties is studying Spike.
Secret of My Excess made it painfully clear that nopony native to Equestria knows much about dragons or the dragon lifecycle. Twilight didn't have any books that she could consult, didn't try asking Celestia for help, and went to a pediatrician and a veterinarian as well as Zecora. Additionally, Fluttershy wasn't even aware that dragons could talk before meeting Spike.

As Celestia is too busy to watch Spike full time, as soon as she completed a few preliminary studies to make sure that he wasn't a serious threat, she entrusted him to the care of her most trusted and faithful student for care and observation. Presumably, some of that royal business that Spike returns to Canterlot for is to be examined by Celestia herself.
 * That makes a lot of sense. The only one in Ponyville who knew anything about dragons was Zecora, a zebra from a faraway land. We haven't seen another baby dragon in the series yet, which implies that they're VERY rare, and if they're going to be raised by a pony they're not going to be raised by just anypony.

Spike will continue to grow and change throughout the second season
Although at a much slower and controlled pace than what was seen in "Secret Of My Excess." His greed will still be present but controlled and instead of taking things he'll start working to earn them instead which will still allow him to grow rapidly but not nearly as fast as he did on his birthday and the final form will be far less monstrous than that see but less "cuddly" than the form Twilight magicked him into in "The Cutie Mark Chronicles."

The Fire Ruby that Spike gave to Rarity will become a Chekhov's Gun
Spike mentions that he's been aging the ruby in preparation for eating it. Since he gave it away rather than simply eating it, it will continue to grow and store energy that will later be used to temporarily transform Spike into an adult dragon that is not as monstrous as his "greedy" form but even more powerful. It may even be able to unlock a mysterious seventh Element of Harmony: Love.
 * More poetically, it's a symbol of his generosity.
 * It's more a symbol of his love for Rarity than his inherent generosity, Spike is a nice guy and all but I doubt he would have given the gem to Applejack or Rainbow Dash if they'd shown any interest in it.
 * Probably, but it is explicitly said that he would only change back with a great act of generosity, which was fulfilled with him remembering how he had given the ruby to Rarity.
 * No it isn't, in fact they have no idea how to change him back, just that they need to try and curb his greed to stop his growth. Remembering how he gave the Fire Ruby to Rarity purged his heart of greed which is why he changed back to his chronological age. They didn't know that would happen.

Spike will be the next bearer of the Elements of Harmony
It's pretty much know that dragon have very very long lives, and Spike shouldn't be an exception of this: He will outlive everyone in Ponyville. He has shown several ways in which he embodies several of the elements already, more explicitly:
 * Friendship/Magic: He has been Twilight's best friend since he was born, and is the only one who has a direct line with Princess Celestia. Whether if it's his own fire or the parchments that are enchanted is irrelevant: He's the only one who has that magical task.
 * Loyalty: "Congratulations, you're the new Rainbow Dash". Plus, like said before, he has been at Twilight's side from birth.
 * Generosity: In "Secret of my excess" He managed to suppress his greedy dragon nature by remembering an act of generosity he had towards Rarity.
 * Honesty: In "Owls Well that Ends Well" He learns the harm of lying, and often tell the other ponies exactly what he thinks
 * Kindness: Spike is always helping out the ponies with one project or another, even if the task is menial, like using his fire-breath to cook cakes and re-heat things and shows great concern for Fluttershy when she's missing in "Feeling Pinkie Keen."
 * Laughter: While his sense of humor is less bubbly and more wise-cracking Spike is still a funny guy who often manages to find humor even in bad situations
 * Since Spike seems to embody all of the elements of Harmony there may even be a time where he's tasked on taking them all on and combining them with his dragon powers to save Equestria.

Spike's crush on Rarity started with her cutie mark.
Seeing as how he's obsessed with gems (being a dragon and all) Rarity's cutie mark was initially the main reason he developed a crush on her, though that was a subconcious reason. Over time, he did start liking her for other reasons, though.

Spike is only with Twilight because she's the one who hatched him.
Dragons must be very rare in Equestria, seeing as how so few ponies know anything about them and we've yet to see a single other baby dragon in the series to date. As such, if a baby dragon were to go into the custody of a pony, it wouldn't be given to just ANY pony. The reason Spike is with Twilight is that she was the one who hatched him, so he has a special emotional bond with her. Not a maternal bond, but still a very strong, unbreakable bond. As a result, Spike was sent to live with her, if partially for his own sake. Without her, he could go into a deep depression, which could also explain why he was so quick to run away the moment he felt "rejected" by her in Owl's Well That Ends Well.

Celestia fought, and possible killed, Spike's mother.
Given how protective a dragon is of their horde, they probably don't leave their eggs just lying around. From the reactions of various ponies, dragons are known to go on the occasional rampage, and from the power even a non-combative dragon has displayed, Celestia is one of the few entities that could fight them. So, after a dragon either died or fled, she left her horde behind for Celestia to examine, complete with an egg.

Whether Spike knows about this, and how he would react, are yet unknown.

Spike sees Twilight as a sister.
Word of God Faust has confirmed, it was Princess Celestia who raised and trained Spike before he ended up living with Twilight Sparkle. However, she felt that they both belonged together seeing as it was Twilight who hatched him. This would explain why during the beginning of winter wrap up he said,"You're not mommy," to Twilight. Because he saw Celestia like a mother figure. But Spike does care about Twilight. Like in Owl's Well That Ends Well, when he runs away because he thinks Twilight doesn't love him anymore. He was also going out of his way to frame Twilight's pet owl, who was being favored by the girls at the time. It's like a child being jealous of the new baby, and Spike wanting the attention from his family (twilight). Also, Celestia wouldn't just give a young mare, a kid that she barely knows. Unless they had a special connection. Just like in the The Cutie Mark Chronicles, it has been confirmed that friends may have a special bond that they may not even know about yet. In Secret of my Excess, it was shown that Twilight is the only one who gave Spike presents for his birthday back when they were in Canterlot together. Confirming that they only really had each other when they were little. It should also be noted that in Baby Cakes, Twilight states that she knows what babies need, in order to be properly taken care of. Now she was only a little filly, but in her spare time, she probably helped Celestia raise Spike, sorta like how a big sister would help the mom take care of the baby.
 * The show may change the idea for Spike's background. This idea was by Lauren, and seeing as she sadly, is no longer a major part of making FIM episodes, this may change. She said herself, the show may treat it differently.
 * In Cathy Weseluck's interview, she states that Spike does seem to share a big sister-little brother relationship with Twilight (she didn't outwardly say it, but it was heavily implied that she meant Twilight)

Spike and Rarity will have kids.
Despite their difference in age, Rarity will realize Spike's feelings, and overtime return them. As shown in past episodes, he is a different breed of dragon. And so he'll grow at a different rate (much faster than other dragons), and have different appearance than other dragons too. As time goes by, and he grows older, he and Rarity will decide to have kids. Ponies and dragons can in fact breed. They can give birth to an animal called a kirin. Kirins are descended from pony/dragon hybrids.
 * Here's what their kid would look like
 * Wouldn't it be a Blue Eyes White Dragon? Just think about it. Rarity has blue eyes and a white coat...

Spike is a secret agent
The reason he's not seen when he should have been in episodes like "The Last Round-up" or "Read it and Weep"? He was fighting Doctor Hoofenshmirtz while the mane 6 were off doing their own adventures.

The reason Spike hasn't been seen much in Season 2 is...
Because he's also a diplomat to dragon lands for Celestia. He hasn't shown up much this season because he hasn't had much TIME to show up.
 * Interesting theory, but Secret of my Excess, pretty much proves that ponies don't know anything about dragons. So they probably don't interact with ponies, let alone with a baby dragon raised by ponies. Also, if DragonShy and Owl's Well That Ends Well are anything to go by, it shows that dragons keep to themselves, and live in separate areas. I doubt that they have a form of government. They seem like the kind of species that are loners. I always felt that Twilight was just overloading him with a lot of chores to do. He, being the nice guy he is, would help with no complaints. But this would cut into his time with his friends, and Twilight wouldn't really seem to notice it. she'd be too busy either studying, or going on many adventures with her friends. Eventually she and the others would find out about how lonely he can get at the library, and will attempt to spend more time with him. Which will lead to him being more active in season 3.

Spike has no parents, and was created by magic.
Princess Celestia had sensed the Element of Magic in Twilight Sparkle, and so made a change to the entrance exam. Celestia wanted to make the exam more challenging for Twilight, and so picked a challenge that required using a large amount of magic. The new test was bringing something to life. Dragons are tough creatures, due to their thick scales, and thus more resistant to magic. Which would make hatching a dragon, more challenging. However, Celestia knew that dragons are very protective of their babies, and refused to steal a child from its parents. And so, she created a dragon egg with her magic, for Twilight to hatch in the entrance exam. And raised him, with some help from Twilight of course.

Spike's species is from a land far, far away from Equestria, possibly Zecora's homeland.
In the Great Dragon Migration we see in the episode "Dragon Quest", we only see ONE other wingless dragon. (the one with the huge tail) The other dragons even point out that he has no wings and question his dragon-hood because of it. Twilight knows his egg was found, but not who found it and where it was found. The lack of wingless dragons at the migration could imply that his species is not native to Equestria, rather, it is a rare species that is found far, far away. Zecora was the only creature in Ponyville who knew anything about dragons. So, Spike's species is from Zecora's homeland. His egg was stolen by a travelling merchant who hoped to sell it in a faraway place. Somepony found the egg at a market in Canterlot and was unable to identify what type of dragon egg it was. Intrigued, the pony bought the egg and brought it to Celestia in hopes that she or her students could figure it out.

Spike's species can only be hatched by magic.
His species is capable of using magic, and their eggs can only be hatched by use of magic.

Spike will grow wings.
Spike grew up in the show so far through magic and being greedy and selfish. Every other dragon that we've seen so far in the show is greedy and selfish. Who's to say he won't grow up differently and possibly get wings because he's NOT greedy and selfish like every other dragon we've seen?

The Secret of My Excess- It shows him growing up, by greed growth. But how do we know that Greed-Growth is the only way he'll grow up? It's most likely a malformed (Not formed correctly), and evil version of how he'll grow up. Now that he's no longer selfish, he may look different when he's older.

Cutie Mark Chronicles- That version of him was created by magic, by twilight. It seems like that was just the newborn version of him, blown up to a larger size. And besides, we didn't even see if that version of him had wings. All we saw was his feet and his head. And as for the picture on the crate his egg was carried in, it was just to show what Twilight was suppose to do with the egg (it simply showed that she was to use magic, to hatch a dragon). As shown in Dragon Quest, ponies know literally nothing about dragons. They probably had no idea what the dragon would've looked like when it hatched. It was just a guess.

He's still just a baby dragon. His wings may grow in later. Or maybe he's just a late bloomer.
 * So... Growing up differently will make him look like all the other dragons?
 * What I mean is, his look when he was Greedy was simply a malformed (Not formed correctly) version of how he'll look when he's grown up. Now that he isn't greedy anymore, he'll grow up naturally. Meaning that he'll grow up like all the other dragons, with wings. It never said anywhere that dragons only grow up by practicing greed, but only that it accelerates their growth, and turns them into mindless beasts. None of the dragons we've seen act like that. The adults we saw in DragonShy and Owl's Well That Ends well could speak English (unlike Greedy spike), and weren’t necessarily greedy, but protective of their hoards. The dragon in DragonShy was being complimented by Rarity, only to find out she only wanted to steal his belongings. And the Dragon in Owl's Well That End's Well, was simply being territorial. Seeing another dragon in his cave, eating his food would set off his instincts. As for the teenage dragons, they were simply jerks. They weren't greedy at all, and yet it shows that they've grown. Also, Spike's grown since the Cutie Mark Chronicles, and yet didn't do it by being greedy.
 * The teenage dragons were acting pretty close to how teen Spike was, if less focused on hoarding. Adult!Spike was capable of understanding the ponies, and reacted more calmly the dragon from DragonShy, as he only defended himself with minimal force, and only after the Wonderbolts cut his spikes/spines/frills off. He was also talked down without Fluttershy's stare being used on him. We don't know how the two adults obtained their hordes, but all reactions imply that it was the same way that Adult!Spike got his. Finally, accelerating his growth doesn't mean, or even imply, that he would grow up malformed. All evidence points to Spike's growth in Secret of My Excess being sped up, but not taking a different path.
 * While Adult!Spike was capable of understanding the ponies, and reacted more calmly the dragon from DragonShy, that dragon could fully speak English along with the dragon in Owl's Well That End's Well. Adult!Spike, couldn't even speak. Which is why I thought that perhaps when Zecora said, “he'll turn into a monster,” that his Greedy form was a more monstrous result of a grown dragon practicing too much greed, which resulted in him losing his ability to talk. The dragon from DragonShy was only hostile because a certain Rainbow colored pegasus kicked him and screamed at him to get out, while he was sleeping. I'd be angry too. Besides, since the form in The Secret of My Excess was an accelerated form of a dragon when they practice too much greed, their form would be more monstrous. I feel that a dragon grows up normally, by practicing greed a little bit every day. It takes time, which makes it longer for them to age, but they eventually grow up. They still become greedy, but do are much less than they are through Greed Growth. And so become standard dragons with wings.
 * Why do people assume that adult Spike was incapable of speech? Adult dragons just don't seem to be big on talking. While the Owl's Well dragon spoke without prompting, the Dragonshy dragon had all of two lines, both after Fluttershy stared it into submission, and the adults from Dragon Quest were never even implied to say anything. The first episode in the series also established that dragons speak so rarely that most ponies aren't even aware that they can talk. After he reached full size, Spike just plain didn't have anything to say. Going silent for five minutes doesn't mean that a character has lost the ability to speak.
 * Zecora did say that he would turn into a monster, but every dragon with more than ten seconds of focus has shown some monstrous behavior. The red and green adults' had violent tempers and the teens were, well, teenagers. Even aside from the question of how literal that statement was, an adult dragon being referred to as a monster is hardly strange. A well behaved adult would be the oddity.
 * The teen dragons from Dragon Quest showed worse behavior than Greedy!Spike. Some of the background ones without a speaking role might have been nicer than the foreground ones, but that wasn't really shown. Garble and his gang had wings, but no sign of restraint. That doesn't seem to imply that wings come from good behavior.
 * The wings may not come from good behavior, but just grow in naturally overtime. What I think is that, dragons grow a little bit whenever they are just a little greedy. Or maybe greed isn't involved at all with how a dragon grows, but can accelerate the growth process, but like I said before, that growth process creates a malformed, adult dragon. All dragons will grow their wings overtime, but for some it takes longer. Spike is simply a late bloomer. Garble teases him about not having wings, because he can't remember a time he didn't have them. His memories of being a baby, are distant, and long forgotten, and so doesn't remember when he didn't have them.

Spike's lack of wings is the outward sign of a serious congenital birth defect.
And he's going to develop serious health problems as he gets older.

What? You were all thinking it, I'm just saying it.
 * I think spike is just a late bloomer, or maybe since he's a still baby they'll grow in over time.

The reason that Spike grew up so quickly in Secret of My Excess is because...
He usually isn't growing up at all. Because of that, when he started to act true to his dragon nature, his dragon desires and dragon growth spurts all hit at once. If he was acting more dragon like all of the time, he would be growing at a more consistent rate, and would have reached adulthood more gradually.

Spike didn't get along with the Dragons from Dragon Quest because they're a different type of dragon
It's implied that spike may be a wingless type of dragon. However, he didn't know that he may be a wingless dragon, and simply joined the winged dragons in hopes of fitting in. But really, he is a type of wingless dragon, and would get along much better with his breed of dragon, having much more in common with them, and it being easier to live with them.

Spike lost interest in Rarity.
At the end of "A Canterlot Wedding Part 2" we see him dancing with her sister, Sweetie Belle. Maybe he decided that being with someone closer to his age would be a tad less squicky?
 * At weddings the ring bearer, which is Spike, dances with the flower girl, which was Sweetie Belle (well, one of them anyway)
 * Does this mean that he also danced with Apple Bloom and Scootaloo?
 * Probably
 * During The Cutie Pox incident when Twilight gets Rarity's hairstyle Spike fawns over her and completely disregards Rarity, who's standing right there! Guess he just REALLY liked her mane...
 * Might also have something to do with Rarity treating him like a "cute little boy", instead of an equal lover, in Dragon Quest. Spike... didn't really appreciate her compliments in that episode. Perhaps with this "awkward aunt" act Rarity is trying to slightly shake off Spike's adorable, but potentially troublesome crush.

Despite the introduction of Shining Armor, Spike and Twilight are still like brother-sister
Based on dialogue from previous episodes, it's implied that Spike and Twilight always had a strong bond:


 * Owl's Well that ends Well he was afraid that Twilight didn't love him anymore. Showing that he really cares about her opinion, and would do anything to please her. Which shows that they must have some kind of affection for each other. It also shows that he loves his job as Twilight's assistant, and won't let anyone take away his job. Also, Twilight was the only one that went looking for him after he ran away, and the only pony (with some help from the owl) that saved him from the dragon. She also says that no one could ever take his place.

And that knew each other ever since they met:


 * Secret Of My Excess mentions how for every birthday he had, Twilight was the only one that gave him a gift. Sure he only got a book, and he didn't seem to thrilled about it, but that proves that these two stuck by each other.
 * Another small example would be, when Twilight takes him to the pony doctor. She takes him there, as if he were just any normal filly or colt. She didn't even consider that because he's different, that they he may be treated differently. That alone seems touching.


 * Dragon Quest: In the end, when spike says the ponies are like family to him, they all, including Twilight, give him a hug, showing that they feel the same way. And the picture of baby Spike with Twilight in the final scene from Dragon Quest, implies that she did know him from the moment he was hatched.

Now, as for Shining Armor, look at it from Twilight's perspective. Spike is her loyal friend. He's always willing to help her out when she really needs it, and was there for her when she first arrived in Ponyville, and has lived with her ever since. But that's the thing. She sees him everyday.

For Shining Armor it was different. He was someone that she could look up to. He was a mentor to her, and her very first friend. He taught her things like how to fly a kite, and helped her with her magic. Spike wouldn't be able to do this. Not only would he be a baby, but '''in the flashbacks, Twilight didn't have her cutie mark yet. So he didn't exist yet!' Shining Armor was probably her only friend before'' she became Celestia's pupil, and thus also before she met Spike. Twilight mentioned they drifted apart, and that's probably the point in time when the drifting happened - when Twilight became Celestia's pupil. And also, she said she hasn't seen him since she moved to Ponyville. she misses him. The song is meant to add more depth to that. It was to let the audience know what their relationship was. For spike, we already know what their relationship is. Just watch Owl's Well That End's Well, and Dragon Quest. It pretty much shows that they're like family to each other. He's like her l.b.b.f.f (little brother best friend), and those episode worked fine without a song because we didn't need them.


 * An alternate theory that could also be accepted is: Word of God suggested that Celestia took to the initial raising of Spike, given the general lack of pony knowledge on dragon raising, only giving her to Twilight as an assistant when both were mature enough for it. Hence, the Twi/Spike relationship - prior to being sent off to Ponyville - would be more formal, and becoming more sibling as they both learned to adjust to Ponyville. This would also be consistent that leaving Shining (whom she still probably saw every day while at Canterlot), her relationship with Spike would be upgraded to the sibling nature to make up for not being around Shining.

In case you're still skeptical here: "Spike:You're more than friends. You're my family"

She loves her brother like a friend. She loves Spike like a brother.

Spike has his own friends, who he regularly hangs out with.
Because it would be weird for a guy to always hang around his older sister's friends, and he doesn't get that much screen time. When we don't see him, assume he's with his own friends. I don't know who, so let's just say Snips, Snails, & Big Macintosh.
 * It does seem to make sense, since it's shown in The Secret Of My Excess that he has enough friends that he could get tons of gifts from, when he turned greedy. It's shown that he knows a colt called Lickety-Split (similar to the g1 pony from the movie). We've also seen that the cutie mark crusaders have interacted with him before, just offscreen. We probably just don't see him hang out with them much, since he's practically married to his work, and seems to have fun hanging out with the mane 6 much more. Sure it may seem weird to hang out with a sister's friends, but many siblings do that often, and the mane 6 seem to enjoy having him around. They don't seem to be complaining.

Spike hangs out with the CMC off-screen often
That's why he doesn't get "invited" to anything. He has his own stuff going on.

Spike is giving Celestia reports on Twilight's behavior.
With express orders to contact her when it looks like Twilight will do something dangerous. He might not have been doing this since the beginning of the series, but certainly since Lesson Zero. That's also why Celestia was waiting in the Starswirl section of the archives in It's About Time.

Spike isn't seen much because he goes to school
Considering the fact that he's still treated like a child, when twilight and spike moved to ponyville, he was enrolled in an elementary school, like the one the CMC are in. However, because of his busy schedule, helping in the library,he has to go to school at a different time, which is why we don't see him in class with the CMC. Or perhaps he goes to another school in Ponyville (it's never stated that there's only one school there, and then goes back to the house to do chores. There's also the possibility that Twilight home-schools him, and has him do homework at the treehouse.

Apple Bloom is adopted.
This explains why there where no parents AND no Apple Bloom in sight in Applejack's flashback, why Apple Bloom is so much younger than her siblings, why Apple Bloom doesn't have an fruit-related special talent despite every snigle other person in the family having one, and why Apple Bloom is so desperate not to lose Applejack as a sister.
 * She's adopted, but she's a cousin. Let's just say that before they caught that tree saboteur, there was more than one tragic apple-bucking accident at Sweet Apple Acres.
 * I disagree. I think she IS Applejack and Bic Mac's younger sister, it's just that she wasn't Applejack's focus in the flashback and may have been a baby. Too young to stand along Granny Smith and Big Mac as Applejack left,or maybe not even born yet.

Apple Bloom's cutie mark WON'T be apple-related.
In Call of the Cutie, Apple Bloom made a fuss about thinking she'd get an apple-related cutie mark. Instead, what if she doesn't? It offers the opportunity to slip in a few words about how even though she's "different" to Applejack, Macintosh and Granny Smith, they're still all a family.

Apple Bloom will work with Rarity on something.
"Show Stoppers" hints that she has a knack for designing and organizing, talents Rarity can appreciate and put to good use. This could easily help Apple Bloom discover her cutie mark, though this could just as easily be set after she discovers her ability, as that could bring it to Rarity's attention.

This could also cause either Applejack or Sweetie Belle to develop a bad case of Green-Eyed Monster: Applejack might feel slighted that her baby sister is spending so much time with Rarity instead of with her, while Sweetie Belle idolizes her sister and could get upset that Apple Bloom's getting to help while she's not allowed.
 * Alternatively, Applejack will detest Apple Bloom's collaborations with Rarity because AJ simply doesn't like Rarity's prim and proper ways; even after settling their differences in "Look Before You Sleep", AJ and Rarity are still derisive enough of one another that they're willing to crack jokes over the tension ("She won't even touch mud unless it's been imported!"). There's also the matter of Rarity's bourgeois attitude being similar to Aunt and Uncle Orange...AJ would prefer her little sis to be Closer to Earth just like everypony else in the Apple family.

Apple Bloom already has her cutie mark.
Her cutie mark is special: It's completely invisible. It signifies her ability for tactical espionage. It's so secret that even she doesn't know about it.

Apple Bloom’s mother is really Applejack.
The Apple parents never seem to be around. In "Bridle Gossip", Applejack tells Apple Bloom she'll tell Big Macintosh on her, conforming that Big Macintosh is the highest authority figure, and that the parents aren't just off-camera. As seen in the flashback in "The Cutie Mark Chronicles", AJ's parents weren't around when she was a filly either, suggesting they died when she was still young. Significantly, Apple Bloom isn't around too. This leads to the conclusion that Apple Bloom is in fact the result of a teenage pregnancy, and they're just passing her off as Applejack's sister to avoid embarrassment. As for who the father is, well, considering Applejack's love for her family…
 * Maybe the father is just some ex-coltfriend AJ had in the pony-version of high school. Either way, its unlikely Hasbro would approve of any hint of teenage pregnancy in the show.
 * Applejack only seems to be in her early twenties in the show (in human years), and Applebloom seems to be about eleven or so, just by how she acts and talks. Unless ponies can reproduce very early, this is unlikely, though something Applejack might do.
 * Alternatively, Apple Bloom is Big Macintosh's daughter, from a previously relationship with a mare who may now be dead.
 * But can you really see that happening to Big Macintosh?
 * Eeeyup.
 * Another possibility is that Apple Bloom is the daughter of Big Macintosh AND Applejack, they're just telling her that their siblings in order to hide the fact that Applejack got pregnant at a really young age, and they were forced to get married. This would also account for the fact that Apple Bloom's coat is a combination of Big Mac and Applejack.
 * You'd expect that someone else in the small town of Ponyville would tell her that her "big brother and sister" are actually married. Incest would be slightly easier to cover up from everyone.
 * Would the bearer of the Element of Honesty really live a lie in that way?
 * alternatively Applejack, Applebloom, and Big Macintosh are all the same person

The lions didn't just happen to be there.
They wandered off while Fluttershy wasn't looking, and that's just as far as they got before Apple Bloom showed up with a whip.
 * Well… that's what "happened to be there" means. It's not like they materialized out of thin air. Sure, there can be an explanation for why they're there, but it's insanely unlikely. Especially given how often we see animals running loose (never).

Apple Bloom and Diamond Tiara will eventually become friends or Friendly Rivals
Well, they'd better at least tolerate each other for the sake of the relationship between Sweet Apple Acres and Barnyard Bargains.

Apple Bloom's Cutie Mark may have something to do with Zap Apples.
Granny Smith said she had a knack for doing it, and it's one of the things she's seen doing so far that she hasn't slipped up with. This would be a good chance for some foreshadowing, as both the bloom of the Zap Apples (which fits her name) and the fruit itself (which fits with the Apple theme) are shown pretty prominently.

== That comment on This Very Wiki to the effect that Apple Bloom's fleur-de-lis was being replaced in the French dub with a cheeseburger (long since zapped as unfounded) was actually straight from the pony's mouth. == I'm guessing it was an unofficial leak from the studio doing the dubbing.

Apple Bloom's talent really is potion-mixing.
She mixed the heart's desire potion in "Cutie Pox" and the love poison in "Hearts and Hooves Day," so maybe he special talent really will turn out to be potion mixing. She has become friends with Zecora, so it's very possible that she'll learn still more about potion mixing from her. She'll probably realize it when she finally makes a potion for a good purpose, using an apple blossom as an ingredient; that's when she'll get her cutie mark.
 * She's also showed talent at making Zap Apple Jam, which seems to be a related skill set.

AB is the unintentional catalyst for her parents' death.
Bear with me, this is a long one. Consider that Cherilee lived in the 80s, which would make her (if the ponies live on human year scales) in her late 30s to early 40s. One of the things that would make Big Mac a match with her is his age (figure that he's a lifelong batchelor due to being "married to his job", i.e. the farm.) thus putting him roughly 15 - 20 years older than the next sibling (AJ). By the time AJ's born, you're looking at the tail end of the potential birthing period for mares. That late birth (as well as giving birth to two big and/or strong earth ponies) could have done damage to Mrs. Apple's ability to have another kid (and having a kid that late, why push luck again?)

Thus, with that damage, figure AB to be an "oopsie." By that point, with age and the birthing canal damaged, AB would have to be delivered by C-section. Only it doesn't work out, and Mrs. Apple's a goner. Figure Mr. Apple to have a farming accident in grief, and as a result, Big Mac (with the fortunate help of their grandmother) is stuck raising the younger siblings.
 * Sad,but I like this idea. I see good,solid, fanfic material.

Applebloom's special talent is unethical potion-making
Seriously, first stolen ingredients, then mind control.Probably get a poison flask cutie mark.

Apple Bloom's cutie mark will be a house shaped like an apple.
The viewer already pretty much knows that building and designing is her special talent, but it would be weird if the cutie mark wasn't apple-themed.
 * Alternatively, it will be an apple getting hit with a hammer.

Scootaloo will get her Cutie Mark last.
Sweetie Belle and Apple Bloom will finally figure out that you can't get your cutie mark by doing suicidal stunts, and eventually they'll find their true talents. Scootaloo on the other hand will be too stubborn at first and it will take her longer.
 * Technically, you can get your cutie mark by doing suicidal stunts - if, by performing them, you realize that they are what you really want to do and are destined to do.
 * So Scootaloo may become a 'stuntpony' if that's her calling…
 * And she will probably react very badly to getting her mark last, and treat her friends rather rudely, especially the one who gets hers first (which I think will be Apple Bloom).

Scootaloo and Fluttershy are related
Because seriously, that'd be adorable.
 * Impossible. FS would recognize her sister/cousin/whatever, but in The Stare Master it's as if they've never met.
 * They could be unaware that they're related.
 * (Looks up G3 Scootaloo's cutie mark) Hmmmm, that might be something.

Scootaloo is Fluttershy's sister.
Her colors are similar to Fluttershys but much darker.
 * Also, as fillies both are/were weak flyers and Fluttershy's habbit of wing-propelled running is alot like Scootaloo's wing-propelled scooting. Scootaloo's talent has been hinted at being dancing, and Fluttershy is acknowlaged as being graceful herself. It would also be cute.
 * More likely is that Scootaloo is Fluttershy's Ponyville cousin or something.
 * G3/3.5 Scootaloo did have a butterfly as a cutie mark...

Scootaloo's still Cheerilee's younger sis.
Word Of Faust was that Ponies could interbreed, wasn't it? It could explain why she's such a weak flier, being half-Earth Pony.
 * Scootaloo is not a weak flier. She just can't get off the ground much, which is NORMAL for pegasus fillies (this may have been retconned as of "Baby Cakes"). In fact, seeing how fast she can propel not only herself on her scooter, but while dragging along a wagon with two other fillies AND a grown pony (who probably eats lots of cake), once she gets a bit older she'll probably be able to fly like a ROCKET.

Ditzy Doo/Derpy Hooves is Scootaloo's older sister
Given what we know of her, Scootaloo sees Rainbow Dash as the cool big sister that she'd like to have; the reason for this is that the sister she does have is a not-at-all awesome mailmare with wonky eyes and a poor sense of direction. We could well have a flashback that shows us that she saved Rainbow Dash at the cost of her depth perception, ability to focus on her job and intelligible speech.

Spitfire is Scootaloo's sister.
Unlikely. Scoot might be a bit thick sometimes, but if Spitfire, a Wonderbolt, were her sister. she'd have bragged about this to Rainbow at the FIRST opportunity. There's no way that Scootaloo, being such a huge fan of Rainbow, wouldn't have learned that Rainbow herself is a fan of the Wonderbolts.
 * Perhaps Spitfire has a Secret Identity?
 * Spitfire IS the secret identity, i.e. a stage name. Her real name?

Scootaloo's cutie mark would be a scooter.
We just haven't seen her earn it yet. Only time will tell.

Scootaloo isn't a pony.
She's actually the flightless bird greed. The reason she's been called a chicken, and a dodo is because those are two of her core medals. The third one will be revealed in season 3.
 * It's gotta be an ostrich or an emu.

Scootaloo's cutiemark will be Rainbow Dash

 * THIS.
 * Where?! Where's the link?!

Scootaloo thought that Rainbow Dash was the Mysterious Mare Do-Well
It would explain her seemingly Out of Character moment in the episode.

Scootaloo has an older sibling -- and a poor relationship with them.
Such as an Aloof Big Sister who doesn't want anything to do with her, or a Jerk Jock who gives Scoot grief for not being able to fly/keep up with her yet… or a flat-out bully. Or perhaps she's simply not aware Scootaloo resents her always being 'too busy' to spend time with her...

Scootaloo's parents left her in Ponyville so she can learn to fly without too much risk.
This is actually common for pegasus foals, and it's why we haven't been formally introduced to any members of her family yet: they're back home. Their jobs keep them busy most of the time, so they can't visit as much as they'd like or give their daughter the supervision she'd require if they were up in Cloudsdale or another pegasus city.

Scootaloo was in fact, raised by chickens.
I'm kinda surprised that it wasn't brought up sooner. She isn't a chicken and she knows it, but she was abandoned to be raised by chickens. Maybe she's embarrassed by this...

Scootaloo will be a Supreme Chef.
Considering how awful Apple Bloom and Sweetie Belle's cooking are. Although to be fair the former was following directions from Pinkie Pie and the latter followed her mother and did improved a bit (Although still messy.) Scootaloo will end up being the best cook of the three or at least something better. It'll be a nice twist of her Tomboy attitude.

Scootaloo's cutie mark will be a lightning bolt
But rather than linking her to the Speed Force like Rainbow Dash, it will link her to the Morphing Grid

Scootaloo's a Military Brat who ran away from home after getting sick of her dad's moving around.
Says it all, really. It'd be awesome if pegasus aircraft carriers existed.

Scootaloo wants Dash to teach her how to fly.
She can flap enough to propel herself on her scooter, but when it comes to really flying, she hopes to learn from the best. That's the best way to learn, right?

This is what Word of God meant by her being 'too shortsighted to learn how' -- she hasn't considered that if Dash ever does agree to an impromptu lesson, she'd likely expect her to be reasonably adept at flying already. This could even set up a potential plot -- imagine Dash's reaction upon learning her number one fan barely has a grasp on the basics of flight, if that! Given her penchant for Brutal Honesty, poor Scoots'd likely be crushed by her response...

Scootaloo can already fly, she just uses the scooter to go faster
On her scooter Scootaloo demonstrates both a large amount of speed and torque. She can zip around at a high rate and has demonstrated the ability to tow two fillies, an adult pony and a wagon without undue difficulty. This implies that she has well developed wings. However in order to fly unaided, Scootaloo must vector some of her thrust to keeping herself airborne, rather than pushing herself forward. Less Thrust = Less Speed. And Scootaloo is all about speed. So with the scooter she can devote 100% of her thrust to attaining a higher speed. 100% Thrust = 100% Speed, something that Scootaloo likes.

Rather then having a big sister...
...Scootaloo will be a big sister herself. This would actually be a good thing:
 * 1) It'll show what her family is like and put all those rumors about Scootaloo being a homeless orphan to rest.
 * 2) It'll give Scootaloo an episode of character development all to herself, which is sorely needed.
 * 3) It's a good way to show how to react to the changes that a new sibling would bring. Something that the target demographic might encounter.

Scootaloo's parents are Earth ponies.
The episode "Baby Cakes" establishes that ponies may have offspring of another pony race if it's in their ancestry. Scootaloo has Earth pony parents, and since they don't have wings they have been unable to teach her to fly. They lived in a town that was almost entirely Earth ponies and moved to the more diverse Ponyville in hopes of having her meet more pegasus ponies who can help her develop her pegasus abilities like flying and weather manipulation.

Scootaloo has a serious obsession with Rainbow Dash.
Like to the point of spying on her house in cloudsdale whenever she can find a way up there.

Scootaloo is going to become a scientist
When she tries to fly in Ponyville Confidential, it's clear that it's her head that's dragging her down. That suggests that she's not as airheaded as most pegasi, which may impede her flying ability, but clearly marks an above-average intelligence.

Scootaloo thinks that getting her Cutie Mark will make her parents love her...and come back.
That is why she is so obsessed with getting one.

Sweetie Belle has Dyspraxia.
She's clumsy and disorganized for a start, with poor attention to detail (forgetting to wash her paintbrush, sewing a costume with five legs, not knowing what a dressform does even though she must have seen her sister use one...). She's also prone to forgetting things people told her five seconds ago, along with being generally slow to catch on to what exactly is going on. She also has a tendency to wander off alone and let the others talk, and is often found daydreaming. Despite all this however she obviously isn't stupid, just... not quite processing the world around her.
 * Simpler explanation for all that: She's a child.
 * And the others seem much older than her, despite all appearing the same age. One of the easiest diagnostic criteria for Dyspraxia is falling behind their peers and remaining infantile in terms of physical and cognitive development. I've got dispraxia and she reminds me of me as a child, and as she's such a lovely character it's nice to think she could be a role model to other kids.
 * Word of God says that ponies develop faster physically than mentally; the core cast members are all roughly the same age and physically mature, but range from a mental age of 12 to 17. Sweetie Belle doesn't need to have a diagnosable disorder to wind up on the low end of the curve for her age.
 * I'm going out on a limb and say that the reason why they mature physically faster than mentally is that they live in an idealized environment. Because they haven't been exposed to the problems that plague human society, they lack the life experiences that would force maturity. Essentially, ponies live a sheltered existence. Just look at the way they freak out over natural processes like weather not being controlled or animals taking care of themselves.
 * Well they are all clearly adults (holding down jobs and living alone) and they're much harder to diagnose, as the natural formation of personality through life experience and the compensation for difficulties obscures such natural disabilities. Kids have less influences, so the effects are much easier to isolate. Of course you make a good point in that though their development is comparable to humans it is distinct, so unless we have a episode where we're able to watch her trying to catch a ball, doing large amounts of handwriting and looking at triangles on a sheet of paper in comparison to large numbers of her peers diagnosing her is impossible. Still from a simple comparison to Scootaloo and Apple Bloom she is on the low end of the curve, and it doesn't appear to be due to raw intelligence.
 * A recent episode showed the CM Cs bouncing a beachball back and forth and laughing. Initially it seems like they're laughing for no reason, but having read this entry, we can now see that it was a heartwarming moment of Sweetie Belle triumphantly doing something she didn't know she was capable of doing.
 * Going by Sisterhooves Social, Sweetie Belle doesn't seem to have below average physical abilities as much as she is surrounded by above average athletes. Additionally, Rarity is a serious perfectionist, which just draws Sweetie Belle's occasionally clumsiness into sharper focus.

Sweetie Belle will fall in love with Spike and will Murder the Hypotenuse.
Because it would be hilarious.
 * I'd say otherwise if she plans to 'murder' her elder sister.
 * In the season two finale, Sweetie Belle dances with Spike. Should Rarity start watching her back?
 * Yes, yes she should.

Sweetie Belle's special talent is something godlike.
Celestia and Luna's cutie marks match their ability to control the sun and moon, which implies that doing those things are their special talents. Thus, there is precedent for ponies having such talents.
 * It's been heavily hinted at that Sweetie Belle's special talent is singing. Doesn't sound that godlike to me. (Unless you consider the Muses...)
 * Well, it could be singing or songwriting/poetry. Did you see how fast she came up with those lyrics?
 * Rarity is excellent designing dresses, but her talent is to find gems. Just because she can sing doesn't mean that is her special talent. Then again, it is implied that for most unicorns their talent in magic is only tangentially related to their cutie-mark talent.

Sweetie Belle's special talent is destruction.
Burning juice and reducing toast to a grey liquid goes beyond Lethal Chef into Epic Fail territory. She has a knack for creating Disaster Dominoes in both "Sisterhooves Social" and "The Stare Master", so maybe destroying stuff is her special talent, leading to her producing disintegration beams from her horn or something. This would form an interesting contrast with her sister's creative talents, and set up for a nice Bad Powers, Good Ponies situation.
 * Scootaloo ponders 'Cutie Mark Crusader Demolitions' in 'The Cutie Pox'. And how cool would a wrecking ball cutie mark be? A more fun contrast: Rarity, the dressmaker extraordinaire. Her sister Sweetie Belle, with a wonderful voice ... operating heavy equipment at a construction site.

Sweetie Belle will get her singing Cutie Mark once she gets over stage fright.
S.B.'s cutie mark will have something to do with music, but she won't get it until she lets go of her stage fright.

Sweetie Belle's stage fright will be used for a different sort of lesson about patience.
Suspecting that her talent might lie in singing, her friends will attempt to force her into confronting and conquering her stage fright. This instead results in a tear-jerking Break the Cutie moment to illustrate the importance of being careful, as her friends' good intentions wind up unintentionally hurting her. (Obviously, she will not get her cutie mark from this incident, in order to avoid breaking the aesop -- if her talent does lie in singing, it will come on its own, when she's good and ready, as opposed to being drawn out when she's forced into the spotlight.)

Sweetie Belle will attempt the "Want It, Need It" spell at some point.
After all, it 'works every time', right? Surely that makes it perfect for practicing her magic!

This'll be used for a dual aesop: Sweetie Belle learns not to dabble in magic she doesn't understand, and Twilight learns to be more careful about the type of example she sets.
 * The whole thing could be sparked off by Sweetie wanting lessons from Twilight and/or Rarity, only to be disappointed that she's far from a perfect spellcaster. Hence the temptation of trying out a spell that's supposed to 'work every time'.

Sweetie Belle's talent is for Song Magic
It's clear her talent involves singing, and as a unicorn she can use magic. Therefore her Cutie Mark is going to be a Installer Port.

Sweetie Belle will develop an accent.
Because the rest of her family has an out of place accent.

Sweetie Belle's cutie mark will be...
...a bell, symbolizing her singing voice.

The Cutie Mark Crusaders will eventually get their cutie marks...

 * ...and they will be Twice as Fancy!

So what will the Cutie Mark Crusaders' talents be?

 * Apple Bloom: Will turn out to have a Green Thumb and really enjoy gardening.
 * On the other hand, every time she shows up, she has a stealth sequence. Ends up as the rogue of their adventuring party.
 * As of Show Stoppers, Bloom seems to be developing into the fix-it pony with a side of Team Mom. She practically rebuilt, repainted, and cleaned out the clubhouse all by herself and seemed perfectly cheerful doing it.
 * A jar of Zap Apple jam.
 * Scootaloo: A racer. May end up idolizing Rainbow Dash.
 * Sweetie Belle: A mediator who may discover her talent when faced with the Cutie Mark Crusaders potentially breaking up when one of her friends gets her mark before the other two, prompting jealousy from the other.
 * She has a knack for singing. Bard, for sure, probably also the face and team leader because of her calm demeanor.

The Cutie Mark Crusaders will find their talents by giving up.

 * The three of them, after an especially dangerous wacky scheme to get their marks, will finally give up. After splitting up to return to their homes, they'll each come across a seperate mopey blank flank- one of which is probably Pipsqueak. They'll try to help them find their talents, ending up crossing paths with each other without noticing (for transition's sake) and they'll gain their cutiemarks at the same time - magnifying glasses.
 * Applebloom's will be pink and have an apple in it, Sweetie Belle's will be blue and with something edible like candy or a muffin, and Scootaloo's will be green with a butterfly.
 * Hey…are you making a PPG Stealth Pun?
 * She'll of course be rather annoyed at it before realizing how cool it is to be able to transform from a crawler to a flier. This also ties into the Fluttershy being her older sister theory. This will ALSO make them never stop being the Cutie Mark Crusadors- they'd just find OTHER ponies' talents instead of their own!

The Cutie Mark Crusader's cutie marks will be (in order of appearance):
Sweetie Belle: A huge bell, almost covering her entire flank. Scootaloo: A wheel with wings sprouting from it. Apple Bloom: An exploding apple.
 * Ponyville doesn't currently have a town crier, but that doesn't mean it didn't at one time, nor that it won't in the future. She likes to sing, and she likes to sing LOUDLY! During the summer break she tries her hoof at making public announcements for the Mayor's office (and a few merchants) and finds her calling. Although she could just shout the news, singing it is more pleasant to passers-by, and allows her to keep it up longer without straining her vocal chords as badly.
 * Like Fluttershy, she never quite gets the hang of flying, but her hero worship of Rainbow Dash won't allow her to give up daring stunts nor "the need for speed". Not grounded, but also not able to rise above being just an average flyer, she will channel her attention to wheeled transportation. She'll become specialized to the point that other pegasus who try to duplicate her stunts will find it's much harder than it looks.
 * Keep in mind that Scootaloo has a G3 Cutie Mark we can compare it to ; I would be shocked if it wasn't at least SOMEWHAT similar to that...
 * A wheel with wings sprouting from it? She'll move to Whinnianapolis, Whinniana, perhaps. Or.. another wheel with wings sprouting from it? This time moving to Detrot, Marechigan..
 * Her friends won't abandon her after they get their cutie marks, but despite their help she'll still be a late bloomer. Although she will become well known about Ponyville as a craftspony and the go-to for repairs, her moment of realization will finally come when an attack by Diamond Dogs, buffalo, or another large group has to be repelled with stink bombs or smoke bombs that she makes herself. The experience will earn her the nickname Apple BOOM, which she will like much more than Rainbow Dash likes hers.
 * Alternatively, a stitch-work apple, after she discovers how good she is at making quilts (and then proceeds to go overboard by making a quilt that covers all of Ponyville)
 * Or an Apple nailed to a plank of wood after she rebuilds the barn all by herself after the Crusaders managed to burn it to the ground by accident.
 * Or, in a moment of Irony, she will be OVERJOYED when she gets a hammer on her flank. Perhaps with a minor name-change/nickname of Applewood.

The Cutie Mark Crusaders will become literal crusaders.
That is to say, they'll get Templar crosses as their Cutie Marks and then depart to the Holy Land to convert all the infidels to the Faith of Celestia.
 * Rather than templar crosses, Apple Bloom will have a red templar cross, Scootaloo will have a white Maltese cross reminiscent of the battle dress of the Knight Hospitaller, and Sweetie Belle will have a black cross like the Teutonic order.
 * Consider the following: Apple Bloom has befriended Zecora. Now why did Zecora leave her homeland (Hoofrica? Maneagascar? Senegallop?) and settle in the Everfree Forest? Zecora's cutie mark is a stylized sun, because she is a worshiper of Princess Celestia (Celestite? Celestian?), but she fled her homeland because some sort of heresy has become dominant there, and Celestians are now persecuted. When Apple Bloom learns of Zecora's backstory, she'll be inspired to lead a crusade to protect oppressed Celestians.

The reason for the Cutie Mark Crusaders' supposed Aesop Amnesia
Rainbow Dash has shown that she does not realize that a cutie mark is earned when a pony discovers who they are just like the Crusaders. And Scootaloo idolizes Rainbow, so she won't get it either and as the de facto leader of the CMC, Scootaloo needs to realize this in order for Sweetie Belle and Apple Bloom to as well. also the Aesop the Crusaders learned in "Call of the Cutie" doesn't change the fact that they still desire cutie marks.
 * I think Sweetie Belle realizes it, Applebloom is catching on, and Scootaloo is ignorant. However, they're not going to say anything until all three catch on.

More Cutie Mark Crusader Cutie-mark Teasing, GO!
When helping to organise Twist's Cuteceneara, the Cutie Mark Crusaders wind up demonstrating an additional skill on top of their current ones, teasing further at their cutie marks:
 * Applebloom gives baking a second shot, approaching it in the way she'd solve practical problems like fixing up the treehouse, and succeeds, demonstrating her gift for adaptability.
 * Scootaloo get the job of fetching party supplies and delivering invitations - we already knows she's perfect for the job with her mad scooter skills, but this task also relies on her memory.
 * And Sweetie Belle, still worried about singing in public, is eased into the spotlight as she plays emcee for the cuteceneara. It helps that someone tells her beforehand that being sister to Rarity, a minor celebrony after the events of "Suited for Success", lends her a lot of credibility on the stage - which was intended to have a Magic Feather effect.
 * Who would teach her how to use the equipment? Maybe a certain different white unicorn with musical talents. One who already has a large fanbase but hasn't had a line yet.

The Cutie Mark Crusaders are a Shout-Out to The Powerpuff Girls.
Applebloom is the leader and has a bow in her hair. Scootaloo is the tomboy, and Sweetie Belle is the nice one. Lauren Faust did work on PPG, and her husband created it! Wouldn't surprise me.
 * It gets better Cutie Mark Crusaders are CMC... CMC as in Craig McCracken.
 * There are plenty of fanart in Deviant ART supporting this theory.

The Cutie Mark Crusaders will all get their cutie marks together
Just like the members of the mane cast got their cutie marks at the same time, the Crusaders will do something to trigger or have some event trigger the appearances of all of their cutie marks. For example, imagine if they had all done the "right" tasks for their talent show performance and gotten the marks afterwards.
 * Maybe Scootaloo will try to copy Rainbow Dash's Sonic Rainboom in order to make something like this happen…
 * And perhaps while on a SCOOTER!

Scootaloo and Sweetie Belle's Cutie Marks will be tweaked versions of their G3 ones
Ponies typically keep their general Cutie Mark design throughout the gens.

The Cutie Mark Crusaders will get cutie marks when…
Scootaloo does a Sonic Rainboom on her scooter.
 * Okay. Now that's just EPIC!!!!!!

At least one of the Cutie Mark Crusaders will obtain her mark accidentally.
As in she won't obtain it while trying out random things to 'force' her talent out, but simply while doing something she likes and enjoys. The way Twist earned her mark without intending to in "Call of the Cutie" was Foreshadowing. This will naturally cause tension with her friends, as she won't be able to explain to them how she got it in a way they can easily mimic, making them think she's holding out on them.
 * It will probably be Apple Bloom or Sweetie Belle, since they're generally more relaxed and open than Scootaloo, who is ALWAYS trying to force her cutie mark. Most likely, Apple Bloom, since it's implied Sweetie Belle will get hers when she sings in front of a crowd. Apple Bloom's talent seems to lay in construction or repair. She'll probably be helping out AJ or Big Mac when she gets hers, presumably when she can't go crusading with Sweetie or Scootaloo. Sweetie will take it a lot better than Scootaloo, who will… given her personality, fling into full jealous brat mode and un-friend Apple Bloom/mock her hammer and nails Cutie Mark.

The Cutie Mark Crusaders will get their marks at the same time… and won't notice at the time.
They will be so busy plotting their next plan that they completely fail to notice the marks' appearances. The mane cast will see, but decide to sit back and wait to see how long it takes.
 * It could be a similar event to the Sonic Rainboom, but much smaller and seemingly less impressive.

The Cutie Mark Crusaders will become Discord's Quirky Miniboss Squad.
but to "thank" them, he'll magically age them up and cause them to go Brainwashed and Crazy.

One of the CMCs will gain her cutie mark, and it will severely strain her friendship with the others.
There are good reasons for any of them to be the likely first, but this plot is downright inevitable.
 * The most unlikely to get her first is Scootaloo, since that will cause the biggest strain. or, if she IS first, she'll be very braggy about it and ditch her friends only to learn that hanging out with Diamond Tiara and Silver Spoon isn't that great and be the moral of the episode.

The CMC have already found their Special Talent.
Their collective Special Talent is searching for their Special Talents! The reason their cutie marks haven't shown up yet is, seriously, what would that even look like?
 * An Ouroboros
 * A blank flank
 * Interesting theory, though how would it work? It's like an oxymoron. Once they realize they have cutie marks for trying to find their cutie mark, they will no longer have to spend time looking for their cutie mark since they already have one. At that point, it would defeat the purpose of a cutie mark: to show what a pony is going to do for the rest of its life.

The CMC aren't as fussed about finding their special talents as it seems to the Mane Cast, they just get really fired up at the start of each new project.
Rather than persistent Aesop Amnesia, the three realize that looking for their Cutie Marks means they can goof around trying all kinds of crazy things to see what they're good at; they seem so hellbent on fleshing out their talents because they're all energetic young fillies that get excited over each new thing they try. When one or all of them gets their cutie mark, they'll probably continue behaving exactly the same way because it was doing all those random fun activities together that they bonded over, not their blank flanks.

Pipsqueak will become the fourth Cutie Mark Crusader.
He's a blank flank just like the three. It's plausible that he'll be the first boy to join the group.

The Cutie Mark Crusaders' Special Talent really is Comedy.
Most CMC episodes (especially The Show Stoppers) are comedy episodes. So yes, their special talent really is Comedy. They make us, the viewers, laugh.

The Cutie Mark Crusaders will get more members, and will eventually become an organization.
Members who get their mark will receive the honor title "Templar" and will serve as guides and advisors for younger members.

The Cutie Mark Crusaders will get a "falling out" episode or similar
It seems that every mane character has had a breakdown episode, so why not pass it on to the kids as well? It would make more sense that the Crusaders have some sort of mass falling out, since it would affect all three. Not really sure how this would come about, but would make for an interesting storyline.
 * Maybe after one of them gains a cutie mark? Or there could be jealousy over one of the trio making a new friend, or even getting In With the In Crowd somehow...

The CMC will have a redo of the theme song performance.
Except this time, it will be at a much bigger event than a talent show (can't think of any ideas for this event). And this time, they will actually manage what they are good at (A.B. designing the set, Scootaloo doing the choreography, S.B. being the lead singer). Of course, a huge portion of the episode will center around S.B. trying/being pushed to overcome her stage fright.

Each of the Cutie Mark Crusaders will have an episode where they spend more time with the other Crusader's Cool Big Sis/Personal Hero.
Apple Bloom already had her training under Rainbow Dash in "Call of the Cutie", and Sweetie Belle obviously came to admire Applejack during "Sisterhooves Social". This theme will be continued with Apple Bloom spending time with Rarity, and Scootaloo getting scenes with Applejack and Rarity. Possiblities include:
 * Apple Bloom and Rarity: Apple Bloom proves more useful around the boutique than Sweetie Belle. See also the "Apple Bloom will work with Rarity" WMG above. Would likely include Call Backs to "Sisterhooves Social".
 * Scootaloo and Applejack: Scootaloo sees how she competes with Rainbow Dash and tries to kickstart a rivalry with her as well. Bonus points if this includes the little pegasus baiting her by calling her chicken.
 * Scootaloo and Rarity: Scootaloo's scorn for all things "too girly" leads her to dismiss Rarity, upsetting Sweetie Belle in the process. (This could also be combined with her insulting Applejack for not being as cool as Dash, straining her relationship with both her friends and leading into an episode dealing with her hidden jealousy over their sisterly bonds.)

The Cutie Mark Crusaders will attempt to focus on cutie marks one Crusader at a time.
Eventually the Crusaders will pick up on the fact that cutie marks are very individual and, thus, decide that the best strategy is to focus on one Cutie Mark Crusader at a time. The end result will be that one Crusader being put through more abuse than they do when they work as a group.

The CMC will get their cutie marks all at once...
...but not until they find three more members. Bonus points if Pipsqueak is a member. Then some big event like a season finale or season premiere they'll show their stuff and get their cutie marks.
 * Fridge Brilliance: Maybe their special talent is finding new members for the Crusaders.

If the Cutie Mark Crusaders ever get any of the Elements, they won't have the same ones as their older sisters/role model.
After all, they're completely different characters; why would they get the exact same Elements?
 * This could even provoke some jealousy if they manage to get one of the 'wrong' elements to react, like Apple Bloom or Sweetie Belle proving their Loyalty.

The Cutie Mark Crusaders will try borrowing the Elements of their siblings/role models in hopes of earning their marks that way.
They do so fully intending to return them before they're missed; naturally, however, things don't work out that way. They also can't get the Elements to work properly for them -- especially Apple Bloom with the Element of Honesty, as she gets caught up in a Snowball Lie trying to keep what they've done from Applejack.

Celestia, of course, will be aware of what happened from the start and secretly observing/permitting it to see if they are capable of using the Elements at all, as well in hopes of their learning how to embrace their unique talents.

One of the Cutie Mark Crusaders will actually be upset when she gets her cutie mark.
She'll be reluctantly trying something with the others, only to find she actually really enjoys it... but when she realizes she got her mark for it, it causes her to Freak Out due to not fully understanding that a cutie mark doesn't completely define who she is, and that she's the one who gives it meaning.
 * This actually sounds like a great episode with a good moral. It even sounds like something from a friendship report.

The Cute Mark Crusaders WILL get their Cutie Marks. But it will cause a So What Do We Do Now? moment.
Until one of the main ponies gives them the idea to help OTHER ponies without a Cutie Mark.

The Cutie Mark Crusaders will give a What the Hell, Hero? speech to the mane cast.
Let's just say the girls objected to something that the Mane Cast did something hypocritically that completely contradicts the Elements of Harmony. Perhaps they'll call them out for not allowing a mule in?

At least one of the CMC will discover a talent/calling that will surprise the Mane Cast as well.
Twilight and the others likely have their own guesses about what talents each of the Crusaders have, and are just waiting for them to figure it out on their own, expecting to deliever An Aesop about listening to the advice of those Older and Wiser than you. However, to their shock, one of the Crusaders actually will discover her calling and have it turn out completely different from what the older ponies expected, teaching them a lesson about not making assumptions or presuming to know somebody better than they know themselves.

The Cutie Mark Crusaders will get their marks in three consecutive episodes.
The first episode opens in Zap Apple season, with Apple Bloom getting a Zap Apple jam cutie mark just before the opening titles. The next episode, Granny Smith passes away in her sleep and Sweetie Belle gets her cutie mark singing at the funeral. Scootaloo gets hers in the third, the what-do-we-do-now episode.

The Cutie Mark Crusaders will have a fourth dark colored member join and then they will all get their Cutie Marks

 * First, Sweetie Belle will get a crown Cutie Mark to represent the fact that she is a born leader
 * Next, Scootaloo will get a sword Cutie Mark for her ability at fighting
 * The dark pony will then get scales to show that they are fair in their judgement
 * Finally, Applebloom will get her Cutie Mark which will be a scythe to show her ability at harvesting things

Sometime after the show ends, at least one of the CMCs will be murdered.
Somepony will never forgive Gabby Gums.

The CMC will bond with the opposite of their sisters in the Mane 6

 * Sweetie Belle will ask Rarity for help with Magic lessons, only to find Twilight is better suited to teach her, and bond over that.
 * Scootaloo will ask Rainbow Dash for flying like her, only to learn is way too soon too fast, and be more comfortable with Fluttershy.
 * Scootaloo's not related to Rainbow Dash, she just idolizes her.
 * OP here, I know, I just didn't want to make the title too long
 * Apple Bloom will enjoy more baking with Pinkie Pie

Each of the Cutie Mark Crusaders will get pets of their own.
Right now it seems that most of the important characters (The mane six, Spike and Celestia) all have pets. Which leaves the CMC out. So what sort of pets would be good for each of the three fillies?
 * It is extremely easy to imagine Applebloom with a pet pig. She already has pigs on her farm, so it would be highly likely that a runt could be born among them. This could prompt Applebloom to take care of it and adopt it.
 * Sweetie Belle would seem like the type to own a small dog. Different from Winona in that it's a Mister Muffykins. Although I'm not sure if it would be a Pekingese, Poodle, Pomeranian or a Pug though... Extra cute and extra yappy.
 * Scootaloo's chosen pet... It'll be a baby chick. Mostly to go along with the "Scootachicken" meme. Or something different and have a duckling.

Eventually someone in the Apple family will fall in love with a pony from a family that grows oranges.
Just because the romance would be incomparable.
 * Not sure if this makes this theory Jossed or confirmed, but we now know that Applejack has an Aunt and Uncle Orange.

"Granny" Smith is actually the Apple Family's godmother.
A Godparent is any relative that has entered in an agreement to adopt the children of a family member in the event the children become orphaned. In Cutie Mark Chronicles, even as children, Applejack and her brother are living with Smith, and Applebloom couldn't have been born yet.

It could be very possible that Applejack, Big Macintosh, and Applebloom are all from different parents, and may not even be related by blood. Fortunately, they are all Happily Adopted and do not consider blood relation making a bit of difference in who they are to each other.

Big Mac will eventually bake cupcakes with Pinkie
And like his sister's they will be BAD.
 * How bad will they be?
 * Bad enough to free Discord, give Nightmare Moon her own body, and kill Celestia.
 * IIRC, Applejack's "baked bads" were because of fatigue.
 * Alternatively, they will be scrumptious. Two reasons why this would be: one, it would be funny, and two, it'd strengthen his position as The Smart Guy of the Apple Family.
 * Just to be clear: Are we talking about making cupcakes with Pinkie Pie, or making cupcakes with Pinkie Pie?
 * Maybe Pinkie and Big Mac eventually discover that they share a hobby?
 * Wait... Are we talking about making cupcakes... Or cupcakes?

Granny Smith is Really 700 Years Old
She witnesses Luna's Face Heel Turn and (possibly) was the user of the element of honesty when Celestia sealed her sister.
 * There might be something to this, if we can ever sort out the scrambled timeline. Twilight says in "Winter Wrap Up" that Ponyville has existed for hundreds of years, but "Family Appreciation Day" gives the impression that the town was founded only about three generations ago. If Twilight is right, then age and memory loss have turned Granny into something of an Unreliable Narrator.
 * We don't know how long a generation is in Pony years.

Big Macintosh will (somehow), at some point, suffer from Cutie Mark Failure Insanity Syndrome.
Mostly because this poster is curious and thinks it'd be funny if it happened.

Big Mac's name is really Big McIntosh
Big Mac is a member of the apple family. As such, it would seem likely that he would be named after an apple than a computer. There's no apple called a Macintosh, but there is one called a McIntosh or McIntosh Red. The fact that he's red would be more evidence for this.

Big Macintosh is a Retired Southern Fried Science Hero.
Not only is he one of the smartest and strongest ponies in the show, but he managed to pull off a Herd Hitting Attack when covered by a Dog Pile of Doom. Am I the only one who thinks he's done this sort of thing before? He was probably a Badass Labcoat - maybe even Equestria's equivalent of Gordon Freeman (after all, they both barely talk) - who decided he was getting too old for this and settled down on the family farm.

As for his field of study? I'm invoking Rule of Funny and guessing he was a computer scientist... Big Macintosh, anyone?

Big Macintosh secretly collects dolls
Why else would he be the one to take Twilight's old doll?
 * He's a Brony!
 * Alternately, Big Mac keeps the doll because he had one like it as a colt and lost it, and deep down he's a sentimental guy. But it is definitely a reference to bronies and their inner desire for cuteness.

Adding to that...

Big Macintosh was unaffected by the "Want it, Need it" spell.
Why was he fighting so hard for the doll, then? Because a stallion has needs.

Granny Smith is Applejack, Big McIntosh, and Apple Bloom's mother.
Every assumes that Granny Smith is their grandmother because her name is Granny Smith, and because she is visibly old and frail, but there is the problem that we've never seen the intervening generation, i.e., Applejack, Big McIntosh, and Apple Bloom's parents. But presumably, Granny Smith is called Granny Smith because that's her name: she's named for a variety of apple, as are many of the Apple clan, and presumably that was her name even when she was a filly. So it's possible that she is the mother, not the grandmother, to the Apple family; if so, it seems likely that she was widowed not very long after Apple Bloom was conceived. As to why she appears too old to be their mother, perhaps she foaled late in life, or perhaps she is simply prematurely aged. After all, running the farm is clearly demanding physical labor, as is raising three foals.

The reason why the Apple Clan tend to be late bloomers...
Cutie marks are created by a pony discovering their special talent and knowing what they want to do with their life. Members of the Apple Clan have an obvious path set out before them from birth -- but that doesn't mean they know whether or not they want to dedicate themselves to that as their life's work. That's why it generally takes so long; they're not sure yet if they want to follow the family's tradition. Apple Bloom's attempt failed because she was doing it for all the wrong reasons, having no real conviction behind her decision to help hawk apples beside earning her mark.
 * Might be kind of confirmed as of "Cutie Mark Chronicles"; Applejack tried living a "sophisticated" life in the city as a filly, realized it wasn't for her, and made up her mind that she did want to carry on the family tradition after all.

There will be a Trottingham branch of the Apples, with Bramley being one of them
We've established that Trottingham is in an area meant to be a Britain expy, and there are Apples everywhere, so combining the two makes sense. Bramley would be an ideal name, since it's a very British variety of apple (and several British towns). I imagine they would have the Lincolnshire/Yorkshire farmer accent (the closest British equivalent to Applejack's). "This week, Oi 'ave been mostly farmin' Apples..."

There will come a time where we'll learn to never mess with Granny Smith.
I've noticed that they've been giving her plenty of screentime, but most of those instances tend to make fun of her age. If there is one thing that the show is good at, it's showing character's Hidden Depths. At some point, her family will be in danger and Granny will have to lay down the law, or do something awesome. It will then be glorious.

There will be a "Fountain of Youth''-esque episode and it'll show Granny Smith when she was younger.
And she'll be beautiful in her youth.
 * There wasn't really a Fountain of Youth episode, but we do see Granny Smith when she was younger.

Big Macintosh is capable of using Haki or some other form of Ki Attack
Based solely off of his epic repulsion of that dogpile of ponies.

The Apple Family are all carriers of the Cutie Pox Syndrome in latent form.
And usually, it never develops, but does interfere with them getting their Cutie Marks, which is why they are all late bloomers. Applebloom accidentally activated the full blown pox.

Granny Smith was quite Badass in her time

 * I'd say that harvesting Zap Apples, dealing with dangerous bees and timberwolves and founding Ponyville in the process is as Badass as it gets, so Confirmed!

Granny Smith's name when she was younger is Annie Smith.
It sounds generic, I know, but think about it. It wouldn't make sense for a young filly to be called 'Granny', so it's likely she had a similar sounding name when she was young that became 'Granny' as she grew old. Plus, 'Annie' is a good Shout Out to the novel Anne of Green Gables, which Granny Smith in her youth resembles with the twin pigtails.

Granny Smith technically isn't part of the Apple family.
Granny Smith's story refers to her family (her parents and siblings) as "the Smith family", so she was a Smith when she was young. Filthy Rich addresses her as "Mrs Smith", which suggests that she didn't marry into the Apple family. Rather, her husband married into the Smith family and took the Smith name. They then had a son or daughter who married an Apple pony and became part of the Apple family, which is why Applejack, Big Macintosh and Apple Bloom are Apples rather than Smiths. It's not uncommon for people to refer to their two grandmothers and grandfathers by their last names to distinguish them (such as "Grandpa Jones and Grandpa Black"), so Applejack probably had a "Granny Smith" and a "Granny Apple" when she was young. She lives at Sweet Apple Acres and is the local Apple kids' only close relative, so she's considered part of the Apple family, but she isn't actually one by either blood or marriage.
 * Alternatively, her family became known for apples because of her Zap Apples, and Filthy Rich called her Mrs. Smith because Smith is her last name. Surnames don't seem to really exist in Equestria.

Aunt and Uncle Orange are also Diamond Tiara's Aunt and Uncle.
Because of their surname, she isn't aware they're related to the Apple Clan. If she found out, she'd be mortified.

Big Macintosh will be a Sixth Ranger
He's getting more and more screentime.
 * Well, he seems to trade on-and-off with Spike for The One Guy slot in season two. Maybe season three will see a full promotion.

There's a special business deal between Sweet Apple Acres and Sugarcube Corner.
The apple farm regularly supplies ingredients for the bakery, and in exchange Applejack is contractually obligated to advertise for them, which is why she calls everyone "sugarcube".

Sweet Apple Acres is actually quite profitable.
One might get the impression from "Ticket Master" and "Best Night Ever" that Sweet Apple Acres is a struggling farm, but actually it's quite profitable. It's just that Applejack and Big McIntosh plow almost all of their profits back into the business. They are constantly making capital improvements to the farm. In "Feeling Pinkie Keen," Applejack mentions having just installed a new apple cellar, and then in "Lesson Zero," Applejack is having Rainbow Dash demolish an old barn to clear space for a new one. Even in "Ticket Master," Applejack's highest priorities for the profits she dreams of making from the Gala are to repair a barn and to replace a plow.

The Apple family is actually very wealthy
Considering that they founded Ponyville (and probably Appleloosa too), prop up Diamond Tiara's family, and some of them are well-known Manehattan socialites, it seems obvious.
 * Though most of their bits are probably distributed across The Clan and tied up in their towns and farms. Mostly the disaster prone Sweet Apple Acres.
 * I'm skeptical about this, I think the Apple family (or at least the Ponyville branch) might be potentially rich, but they're held back by poor business sense. The Flim Flam brothers showcase how easily they can be goaded into bad business deals (they pretty much gave them their southern field for free, which the brothers were destroying in their competitiveness). And they take time off during the day to sell their cider and failing to meet demand when they could just hire someone to sell the stuff for them (or get Filthy Rich to do so like with the Zap apples) so they can concentrate on making more. And Applejack had prepared a large amount of food that pretty much went to waste because she didn't bother to check what kind of party the Grand Galloping Gala was, not realizing the clientele was pretty exclusive and the party itself was catered.

The Ponyville Apples are not good businessponies.
Whether from lack of experience, senility or genuinely poor business acumen, the Apples don't seem particularly business savvy. That's not to say they're idiots, but they are hesitant to call in for help when needed (Applejack nearly worked herself to death in Applebuck Season), do proper research into prospective markets (Applejack made a huge amount of common foods that anypony could buy at one of potentially dozens of bake shops in Canterlot and tried to sell it at a catered event, which ultimately went to waste), they don't make enough product nor adapt their production schedules to allow themselves to build up a surplus (their cider is quite vital to the survival of the farm but they constantly run out and potentially alienate their customers), and they let their family honor sucker them into a bad deal (they let the Flim Flam brothers harvest their southern fields with zero recompence). That's not to say they're complete failures, but they do make obvious mistakes and suffer for it.

Or they only make money off Cider and Zap apples, and one of those comes just before tax season
The Apples still hold two monopolies, one that appears to be a monopoly for ALL of equestria (the Zap apples). They sell everything else at either at cost, or they sell it at a loss, because of an over filled Apple Market. The Apple Family is all across Equestria, and since Earth Ponies magic is to grow food (they can even make viable Apple orchards in the DESERT), all food prices are VERY low. This is similar to farmers before and at the beginning of the Great Depression, where farmers were struggling, since they simply couldn't sell anything for a profit due to over comptetion from other family farms). Zap Apples and their special cider are the only thing making them money, and either A. the profits only barely outweigh the constant loses they take or B. they have the misfortune of tax season landing right after one of those harvests.

Big Macintosh and Cheerilee will get married.
However, due to scheduling issues, it will be the exact same day as Princess Cadence and Shining Armor. The episode will focus on Rarity being torn between being with high society and being with her friends.
 * That's already been done though.

Big Macintosh and Cheerilee had been secretly dating all along.
Their awkwardness at being thrown together by the Cutie Mark Crusaders was over not wanting their secret relationship to become public knowledge yet.
 * Neither appears at the wedding in the second season finale despite the large number of Ponyville inhabitants in attendance. They used everyone going out of town for the wedding as an opportunity for some alone time together without anyone finding out. A third season episode will center around them trying to keep their relationship a secret because they don't want to be pressured by anyone.

Braeburn will return
Since he's become such an Ensemble Darkhorse, they might realize this and bring him back in some fashion, maybe in Season 3.

Zecora had a run-in with Applejack in the past, which is why Applejack's so scared of her.
Like say, they met when they were fillies and something unintentional on Zecora's part happened between them that left Applejack horrified of her.

Zecora has lost family or friends to crocodiles.
At the time this guess is being made, we have not seen her with Gummy (Pinkie Pie's small, toothless pet alligator). If we see an episode where she sees him for the first time, she will react badly, and if we don't it will still be clear she is not very keen on him.

Zecora did steal Pinkie Pie's song.
Or so it appeared to Pinkie. The nursery rhyme Zecora was muttering just so happened to be about an evil enchantress that does evil dances and eats little children. Pinkie, who understands the Zebra language through her reality warping powers, decided she must have stolen the idea from her.
 * Or, alternately: the nursery rhyme is something entirely different that just so happens to mention witches, dancing, or boiling things (perhaps the zebra equivalent of "double, double..."), and Pinkie jumped to conclusions.

Zecora is a recluse or outcast from zebra society.
Zebras are herd animals which live on open grassland. Zecora lives by herself in the Everfree Forest. It seems unlikely that this is normal behaviour for zebras. She may not fit in with her own race any better than she does in Ponyville - otherwise, why would she keep hanging out in the forest and trying to go shopping in Ponyville rather than simply returning to her own home?

Zecora will get a song.
And as implied the rhyme scheme will be amazing.

Zecora's special talent is being a Magical Negro.
More specifically, her special talent is giving advice to non-zebras. If the theories about Cutie Mark Failure Insanity Syndrome are accurate, she may have suffered a case offscreen after the parasprite debacle.
 * You sure zebras even have "special talents"? She seems to have a tribal tattoo in place of a cutie mark.
 * It could just be a tribal symbol often associated with whatever her talent was, there's nothing to indicate that it's not a Cutie Mark.

Zecora's special talent is being an herbalist and chemist.
Her cutie mark is a stylized sun in a spiral or swirl shape. The swirl represents the mixing of ingredients to make a potion, while the sun represents the fact that she uses plant-based ingredients, because plants get their energy from the sun through photosynthesis.

Zecora moved to the Everfree Forest because it is the location of some of the most exotic and potent plants in the world.
Think about it: if you were as gifted an herbalist and chemist as Zecora, the Everfree Forest would be your World Series, or your moon landing. The place is clearly a veritable pharmacopeia of rare, exotic, and potent plants, most of which would be found nowhere else, or hardly anywhere else in the world. That's why she left her homeland to live in the Everfree Forest. She specifically settled near Ponyville because it's a settled community at the edge of the forest, so she'd be able to purchase other supplies and have social contact.

Zecora's rhyming is due to her Translator Microbes.
Zecora can't actually speak the Equestrian language fluently - she's a skilled alchemist but a lousy linguist. So she uses some kind of herb or potion to give her the gift of tongues, but it has the side effect of making her speak in rhyme. When she's among her own people, she doesn't need the potion and hence can talk normally.

Zecora and Princess Celestia are somehow linked.
After all, Zecora's cutie mark is a stylized sun.

Zecora speaks in rhyme as a show of respect to others.
It's part of her homeland's culture. In order for her speech to both rhyme and still get her point across, she'd have to put a little more thought into what she says. Her literally poetic speech is her way of saying "I respect you enough to really consider what I say."

Something terrible happened in Zecora's homeland and she's in Equestria to look for a way to fix things.
A brutal dictator with magical abilities took over her homeland and put a spell on the creatures to force them to work for him. Zecora was one of the few lucky enough to escape. For having such knowledge in spells, cures and remedies, others in her homeland help to get her to Equestria because they see her as their last hope. As mentioned above, the Everfree Forest is home to all kinds of strange and magical plants, so she's living there while she looks for a cure. As looking for a cure to a spell that no creature really knows about could take a lifetime, she's settled down in a home. She can't get much help from the citizens of Equestria because they know so little about certain magical things outside of unicorn spells. Look at "The Secret of My Excess", not a single pony outside Zecora even had the slightest idea of what was going on with Spike, and there's so little knowledge about the plants in the Everfree forest that not even Twilight could find much information on them.

Zecora will have a larger role in season 3.
Zecora was intended to be sort of a second mentor to Twilight, but it didn't come to pass. Seeing as how she has been appearing more often in season 2, it's not unreasonable to assume that her role could expand. Her main role in the show is already to help the characters out with magical issues they know little about, and Twilight can learn a ton of things from Zecora that she can't learn anywhere else, not even from books.

Zecora is somehow affiliated with ZigZag the Grand Vizier.
They're both fairly mysterious characters with magical connections, and they always speak in rhyme for no explained reason. While Zig Zag was dead long before the rule of the ponies, Zecora found some old manuscripts of his and started practicing some of his techniques, which involved speaking in rhyme.

Zecora speaks in rhyme as a way to get in touch with magic.
In "Family Appreciation Day", Granny Smith talked about how all these crazy little things can influence magic in the Earth. By speaking in rhyme all the the time, all kinds of magical properties in plants and potions are unlocked.

Zecora currently has a poison joke infection that makes her talk in rhyme.
She likes it though, which is why she never tried to fix it.

Zecora is actually a Zebroid.
It's extremely odd how they gave Zecora a "Little Pony" character design despite supposedly being a different species from the other pony characters. Much like donkeys and horses can breed with one another, zebras are also able to breed with other equines of different species and produce offspring. Perhaps Zecora is actually one such example. Either her mother or father is a pony. She inherited the same build as a Little Pony and even a cutie mark like a pony. It might also explain why her stripes don't cover her whole body and her small size.
 * She might just be a mountain zebra. They're smaller than other zebra species, about the same size as ponies, in fact. Also, the fact that a zebra has a cutie mark is no stranger than the fact that ponies have cutie marks. That's apparently just something common to equines in this world. Consider also that the mule we saw in "Applebuck Season," despite appearing to be an adult, did not have one. Since a mule must have a pony or horse ancestor, and if you are correct that pony hybrids with other equines will also develop cutie marks, that would lead us to expect an adult mule to have one. More likely, then, is the explanation that something about the hybridization process blocks the formation of cutie marks, which would mean that the fact that Zecora has one militates against your hypothesis. As for her stripes, all zebras have different patterns; that's not dispositive. Most zebra/horse hybrids only have stripes over certain parts of their bodies, and have more horse-like coats elsewhere, which is not the case with Zecora.
 * But she looks more like a plains zebra.

Zecora can glow in the dark.
Well, her new toy apparently can so it might be possible that she can as well.

Zecora illusion dust isn't magical. It's a hallucinogenic compound
We have no evidence that Zecora can directly manipulate any magical field. However she seems to be able to cause illusions with seemingly magic dust. Perhaps it isn't magical, rather it is a non-addictive hallucinogenic compound. There is no magical illusion, it's just all the ponies tripping. Zecora has had training to both resist it's affects and guide the hallucination for those affected.

Carrot Cake is Tiger of the Wind
My Mom said it.

The Cakes are good friends of the Pies.
Related to the "Pinkie suffers from psychosis" WMG on the Pinkie page. Since they don't leave Pinkie unsupervised, naturally they wouldn't let her travel alone either. So if Pinkie wants to go home to the rock farm for a visit, one or both of them is going to have to go with her. So they've gotten to know her parents fairly well, and enjoy their visits to the country.
 * Alternatively, the Cakes are distant relatives of the Pies. Think of it: Cake and Pie...

The Cakes don't live in Sugarcube Corner; they normally keep their toddlers at home with a nanny while they run the shop.
Obviously, we've not seen mention of the Cakes having children, beyond treating Pinkie as one of their own. Sugarcube Corner only has the garret but appears to lack any other residence, implying the Cakes live elsehwere leaving the garret for Pinkie. Thus, by having the tykes stay with a nanny while they run the shop seems like a perfectly reasonable system. And perhaps why the Cakes aren't always frequent in Sugarcube Corner as they are at home tending to their twins.
 * Following this, the plot will initiated when the Cake's nanny has to tend to her own business, and they either can't find a babysitter or Pinkie overhears and offers (read: foists) her services to them.
 * Partially confirmed: Pinkie was their last choice for babysitter (from the other Mane Six)
 * However, this seemed to be guessing that the twins had already been born.
 * "Baby Cakes" establishes that the building does have an upper floor between the shop and Pinkie's living space, and that the twins' nursery is up here. You don't go setting up a room like that (and stocking it with plenty of toys and diapers) unless you mean for it to be used on a regular basis.

Celestia is the "Father" of Pound and Pumpkin Cake
She used her Unicorn powers to impregnate Mrs. Cake. This explains how a pair of twins can be a Unicorn and a Pegasus. It also explains their extreme power at such a young age, especially compared to Sweetie Belle and Scootaloo. Mr. Cake is either in denial or being coerced, you can see it in his reaction.
 * Alternatively, their father is Prince Solaris. Somehow.

There's no infidelity involved between Mr. and Mrs. Cake
They just have closer ancestors with Pegasus and Unicorn blood than Mr. Cake is aware of. Whether or not those involved infidelity is up for debate.
 * Alternatively, Mr. and Mrs. Cake were infertile, and opted to take some experimental magic fertility treatments. It worked, but ended up accidentally expressing the traits of the other pony races.
 * Alter-Alternatively, They solicited donors and the hospital screwed up and instead of Earth, they gave them Pegasus and Unicorns.
 * Unlikely, it wouldn't make sense for them to mention their family history if they used donors. A better explanation would be that they attempted in-vitro but someone screwed and added pegasus and unicorn to the mix instead of Mr. Cake/Mrs. Cake.
 * Not necessarily, if Mr. Cake felt embarrased about his(and/or his wife) infertility, he would come up with an hard to verify family story. The hospital screwing up whatever the technique used, however, seems to be the most likely explanation.
 * According to the "Ponies" section on the Settings WMG, is that all ponies have Earth, Pegasus, and Unicorn ancestors on their past. Applejack and the rest may not know it because they never mated before. So it's perfectly normal for say a Brown Earth Stallion and a Gray Pegasus Mare to have Lavender Unicorn Filly.
 * Or, yanno... Maybe they're swingers in their free time and there was no infidelity because Mr. Cake knew what was going on and was okay with it.
 * Then what breed was the biological father?
 * Kinda squicky, but there might be two biological fathers. Two eggs were released by Mrs Cake's ovaries, she then slept with a Pegasus and a Unicorn in rapid succession(possibly at the same time). End result is each egg got fertilized by a different stallion's sperm.
 * Pumpkin fits; she's a throwback to her dad's ancestor (and takes after her dad to begin with). It's Pound who's the dodgy one; he doesn't look much like either parent. Which suggests that any infidelity that happened was likely (but not necessarily) on the part of Cup's mother.
 * Or he takes after one or more of his grandparents. Genetics isn't just "take looks from both parents and mix'n'match."
 * To clarify: what I was suggesting was that Cup's biological father is a pegasus. She's simply unaware of the fact (or at least was as of the birth of the twins).

Pound Cake's ability to fly is only because he's small enough for his wings to lift him.
Looking at Scootaloo for example, it's most likely that pegasus wings grow at a smaller rate than the rest of their bodies. It's most likely that as Pound Cake grows up, he'll end up with limitations similar to Scootaloo and have to relearn how to fly as his wings grow.
 * Except in the same episode we see he is able to lift and drag Pinkie Pie off the ground. Indicating that those wings are capable of supporting the weight of both a one month old toddler and a more or less fully grown pony at the same time.

Pound Cake's Cutie Mark will be strength-related.
The kid BROKE a metal water faucet! A FOAL broke metal!

Pumpkin Cake will become a chef, with pumpkin-related specialties
Since only Earth ponies can actually grow things, maybe there's still a way a pony of a different race can work around this. Why not by preparing the food?
 * It's never said that ONLY Earth ponies can grow things, they're just much better at it because they "bless the land". And there are always exceptions, look at Fluttershy, for example. Pumpkin Cake might still be able to grow things, particularly if it's in her special cutie mark talent.

Pound and Pumpkin Cake will eventually become heroes of Equestria.
They've demonstrated that they have incredible ability and while the future is still unwritten, there's the possibility that they're destined for something... Or at least be a Rainbow Dash and Twilight Sparkle in the making.

Regarding Pumpkin Cake...
I predict that, because of her unusual magic skills (teleportation, levitation, and self levitation, among who know's what else), I predict that Pumpkin Cake will soon become Twilight's own student and eventuall successor as the Element of Magic.
 * The episode did establish that baby unicorns often have random and sometimes powerful bursts of magical ability. I'm not disproving your WMG here, I'm just saying that what Pumpkin was doing wasn't out of the norm for baby unicorns.

Twist is Mr and Mrs Cake's daughter.
A talent for making tasty treats could run in the family, especially when she gets it from both sides. We see Twist's house in Call of the Cutie, but there's no indication that Mr and Mrs Cake live in or above their shop (and living directly underneath Pinkie Pie would be rather trying), so that might have been the Cake residence. Finally, making more than a few types of candy isn't actually something that can easily be done in a home kitchen, but as the Cakes' daughter, she'd have access to Sugarcube Corner's professional equipment, such as the machine that tried to eat the CMCs in The Show Stoppers.
 * Seemingly Jossed by the events of "Baby Cakes," as it is strongly implied by that episode that Pound and Pumpkin are their only foals.

There will be in-universe speculating about Pound and Pumpkin's potential cutie marks.
Likely involving the Cutie Mark Crusaders making their own theories up, with at least one completely off-the-wall and random idea.

Twilight will get her turn looking after the twins.
Simply so that everyone will get to see her coping with Pumpkin's Wild Magic. (And given her tendency to try and replicate the results of any spell she sees in later episodes...)
 * Ms. Super OCD, looking after babies, who are inherently chaotic? his I want to see!

The Mane Cast will get asked to help teach the twins.
In a nod to fandom speculation, Dash will initially call Pound a prodigy, while Twilight is less eager to label the babies as super-powerful without ample proof and attribute it more to magical surges and typical growth.
 * Dash's praising Pound would probably make Scootaloo jealous and eager to prove herself...

Pumpkin Cake will develop magic akin to Pinkie Pie's powers.
Learning by example, even though nobody really fully understands what exactly that example is, only the results. Including om-nom-nomming on the Fourth Wall.

Adultery was involved in the production of Pound and Pumpkin Cake.
But not by Mrs. Cake. Rather, there was adultery committed in previous generations of the family, on both sides, an uncertain number of generations back. As a result, unicorn and pegasus DNA was introduced into both sides of the family, but was never expressed because both genotypes are recessive to the earth pony genotype. But, when Carrot married Cup, they produced a unicorn and a pegasus as a result, because both were carrying unicorn and pegasus DNA.
 * Still say it was Cup's mother and a pegasus. Unless it happened more than once. Which might explain why the twins are such precocious little scamps.

Pound Cake will grow up to be the official caterer for Wonderbolt functions.
His repertoire of recipes will be quite different from the folks', for obvious reasons.

Cheerilee is a Magnificent Bastard who's plotting something behind the scenes of season 2
Don't know what she's plotting, but every time she has been seen or mentioned, things start going down hill for the episode's main character(s). Alternatively, she could just be a Troll, one that could possibly rival Discord.
 * Return of Harmony: Brought her class to the Royal Canterlot Garden for a field trip. The Cutie Mark Crusaders fight in front of Discord's statue, which eventually lead to his release. Someone even posted a comic of her reaction to his defeat.
 * Lesson Zero: Twilight always had Super OCD. No doubt about that. But it seemed like her typical Super OCD for the first few minutes. However, after Spike goes over the fact that they returned Cheerilee's blackboard to her, Twilight's Super OCD is turned Up to Eleven in the cupcake scene at Sugarcube Corner and just escalates from there.
 * Luna Eclipsed: Pinkie Pie mentions at the beginning of the episode that they passed by Cheerilee house while Trick-Or-Treating. Pinkie Pie then goes on to make Luna's attempts to adjust to Ponyville harder.
 * The Cutie Pox: Not the original poster, but I found it suspect that Cheerilee would on a whim cancel classes for the day and indulge Applebloom's showing off, triggering the full blown syndrome. What IS this pony playing at!?
 * Secret of My Excess: Cheerilee learns of Spike's birthday and conveniently has a present ready for him. Well, she is a friend, right? Why wouldn't she give him a present? Well, first off she didn't know it was his birthday(Or did she?), but was able to pull a present out of her grocery bag! Why on earth would a pony have a hat(A hat that fits a baby dragon, mind you) in her grocery bag? Should it come as a surprise to any of you that her present was what sent Spike into his greedy, destructive growth-spurt?
 * Family Appreciation Day: Cheerilee telling Apple Bloom that it's her turn to bring in a family member on the day Big Mac and Applejack will be harvesting the Zap Apples. Might seem like a coincidence but if you look at her list, Apple Bloom is at the top of the list while Diamond Tiara, the last filly to go, is at the bottom of the list. Either Cheerilee doesn't follow her lists from top to bottom or she did this on purpose.
 * The Super Speedy Cider Squeezy 6000: Did she join the complaining or did she persuade the crowd to second Caramel's complaining?
 * Hearts and Hooves Day: The Cutie Mark Crusaders are an adorable Spanner in The Works, delaying The Plan.
 * Alternatively, their meddling unknowingly gave her Big Mac as an ally.
 * Ponyville Confidential: If Cheerilee had actually been keeping a closer eye on her students, then the entire kerfuffle that the Foal Free Press caused would have been averted. It takes a special kind of ignorance to absentmindedly let a school newspaper go so out of control as to publicly humiliate a great number of town citizens, most of whom shouldn't even be involved in the school itself, including The town's mayor. It's only until the CMC wrote a public apology and everything else died down that she managed to come back and do something about it... Promoting one of the instigators to editor-in-chief.

Cheerilee is still Scootaloo's sister like in G3.
Cheerilee is implied to be about the same age as Rarity in "Cutie Mark Chronicles" and Rarity has a little sister. We didn't know Sweetie Belle and Rarity were related until "The Stare Master", so the Cheerliee & Scootaloo relation has just never been brought up on-screen. As to why Scootaloo doesn't look up to her big sister like her fellow crusaders, it might be because Cheerilee is a school teacher and therefore not "cool". Word of God is that Ponies can 'interbreed', so they could still be sisters despite the fact Scootaloo is now a Pegasus.
 * There is also the fact that Cheerilee isn't a pegasus. Scootaloo would want to look up to somepony that would know the pleasure of embracing the sky.
 * Fridge Brilliance: This would also explain why Scootaloo doesn't attend the same school class as Applebloom although they're the same age. She's just in another form group or something, because she can't be taught by her own sister.
 * This portion may have been Jossed in season 2 episode 1, it shows all the CMCs on a class field trip together. Still, Cheerilee could still be an older sister though.
 * Depending on how Equestrian schools work, this could still fit. Maybe all the class groups went on the same field trip and having Cheerilee was the only older pony able to take charge that day (certainly the only one visible), making it an acceptable break from the "not being taught by a relative" rule. Stuff like that used to happened in this troper's school from time to time.

Cheerilee will become a Sixth Ranger
In season 2, her screentime has been increased sharply. She has also been woven subtly into the mane cast's lives: This has all been carefully set up so that when she eventually joins the group, it will feel completely natural.
 * In "The Cutie Mark Chronicles", it is implied that she used to be a classmate of Rarity.
 * In "The Show Stoppers", she is seen hanging out with Twilight.
 * She's the CMC's teacher...
 * And possibly Big Macintosh's girlfriend in the future.

Cheerilee and Big Macintosh are not romantically involved with each other, but might become good friends.
Kinda in the same way that Spike and Rarity are portrayed. Whether they'll be Platonic Life Partners is still up in the air.
 * It was actually implied that they've been friends, to at least some degree or another, for some time (possibly since they were foals; IIRC, they're of an age). Even if a genuine attraction isn't developing now that the "love poison" has worn off, they seem to be close enough to scheme with each other now.
 * Big Mac would have to be older than Cheerilee because he's a few years older than Applejack, since the Mane six are implied to be the same relative ages (give or take a year or two) and Cheerilee is shown in Rarity's class when they were both fillies. Now the age difference doesn't have to be all that great, it could be as little as two years or as great as the age difference between AJ and Applebloom (in AJ's flashback young Mac is seen with a build comparable to that of some full-grown ponies, although that may just be because he's, well, big.

Shining Armor is Equestria's answer to Link.

 * Does that mean we'll never hear him speak?
 * He does speak. And has the same VA as Braeburn, in fact.
 * It would have been hilarious if Shining Armor was "voiced" entirely with Voice Grunting.

Shining Armour is Twilight Sparkle's Half-Brother.
This would explain them not really looking a like outside of having somewhat similar cutie marks.
 * And somewhat similar manes too. But Pound and Pumpkin Cake already proved that pony genetics are crazy anyway (unless, you know).
 * He does look like Twilight's father though (having a blue mane and similar head shape). He just has the larger build used for Big Macintosh, Rarity's dad, and Prince Blueblood.

Shining Armor is Twilight's younger brother.
Because it's funny.

Shining Armor has been in the military.
Possibly defending Equestria or helping creatures in a neighboring kingdom. If he truly is Twilight's brother, it could explain why we haven't seen him.
 * Confirmed, sort of. He's head of the guards, which is the closest Equestria seems to have to a military.

Shining Armor used to be a jerk.
Which is why Twilight never talked about him, but has since matured after joining the military.
 * Another theory is that the two of them had a highly spirited Sibling Rivalry with Twilight being better at magic while Shining Armor was Book Dumb and a better athlete. Twilight still sees him as her jerky older brother and will try to put a stop to him marrying into the royal family but will find out that he was never really that bad of a guy and will become enthusiastic about the marriage when she realizes it means she'll be relatives (however distantly) with Princess Celestia.
 * After seeing him in action (and in Twilight's flashbacks), we can safely consider these two Jossed. The one 'jerk' moment he has -- his reaction to Twilight's really annoyingly vague accusation that "Cadence" is somehow "evil" -- is both one he shares with everypony else present and decidedly out of character for him (at least partly justified by Chrysalis's manipulations and the constant stress of having to maintain the shield around Canterlot); he reverts right back to being her B.B.B.F.F. once the Changelings are dealt with.

Shining Armor's special talent is protection.
His cutie mark is the same star as Twilight's but on a heraldic shield. His primary unicorn spell will be a force shield. The same defensive bubble that Twilight wielded against Discord. She learned it from him, like how she copied Rarity's gem finding spell.
 * Confirmed that the force shield is a primary spell to him.
 * Adding to this, he may be a Barrier Warrior, and able to weaponize his force fields. (Think Kekkaisi)
 * Along these same lines, he probably got his cutie mark defending Twilight from something when they were younger. The lesson he's going to learn is to stop being overprotective.

Shining Armor's groomsmen are going to be a parallel, Spear Counterpart group to the mane six.
His army buddies, and they'll exemplify the tropes of The Unit. He'll have a creative armor-crafting or gadget-guy unicorn, a close to the earth drill-sergeant type earth pony, a somewhat-unbalanced and shell-shocked Rambo-type who likes to appear suddenly from cover and favors ambushes, a brash and cocky Chuck Yeager air support pegasus, and a dependable but shy support flyer who will be a Gentle Giant. Shining Armor himself takes his sister's role as the leader and spellcaster, and his buddies give him flack for overplanning things and going by the book.
 * Jossed. No groomsmen were in sight.
 * There were three Groomsmen (The Models were Caramel, Cherry Coke and Blues), but still jossed in that they don't speak.

Shining Armor is a figment of Twilight Sparkle's imagination.
Of course, Your Mind Makes It Real combined with her powerful Magic makes him seem real to everypony else. She always wanted a brother.
 * SAME FOR CADANCE?
 * No, just her brother.

Shining Armor is Cadance's Victorious Childhood Friend
He's had a big crush on her since the days when she foal-sat for Twilight Sparkle, but was always quiet about it because he thought that nothing would ever come of it (she's a cerapter and royalty, after all). In fact, he kept sufficiently quiet about it that Cadance somehow didn't put two and two together until her own Love Epiphany. (She proposed to him.)

Shining Armor can create any shape out of force fields
His skill with force fields is such that he can use them to create any 3D shape, not just spheres, much like the Green Lantern Corps and Sue Storm.

Shining Armor wasn't disabled by the Queen's magic.
It was shock from seeing who and what he had spent the past few nights with.

Shining Armor was away at military training when Twilight got her cutie mark.
This explains why we didn't see him in her "Cutie Mark Chronicles" flashback, and why she doesn't have a cutie mark in her "Canterlot Wedding" flashbacks.

Shining Armor is, indirectly, the reason that the rest of the guards are useless.
With someone as powerful as him around, they don't bother to take their duties seriously. Why should they, when he can throw up a shield that can cover all of Canterlot? Hopefully, after seeing him get brainwashed, they'll actually start to be worth a damn again.

Shining Armor is a Barrier Warrior, or at least has magic centering around force fields.
Shining said that only he was capable of creating the shield over Canterlot, and his name and cutie mark have a defense motif.

Trixie has been to the zebra homeland.
She once referred to herself as the "greatest equine who ever lived" rather than simply the greatest pony. This suggests she's met equines that aren't ponies. Her traveling show has likely taken her to all sorts of foreign lands.

Trixie had to live with an abusive family member for a time.
Think about it. She and Eddy share alot of things in common. They're always out to prove they're better then everyone else. In the Ed, Edd n Eddy movie,  If the above WMG is true, it could be possible that Trixie gained her inferiority complex in the same way.
 * This has some scary implications when one remembers Eddy's brother...

In contrast with the above WMG, Trixie use to have a family member she idoled.
Maybe a big brother or sister who was exceptionally good with magic. She could have probably been very close to them, and maybe something happened like they died in an accident, or the more kid friendly version of them just disappearing one day. She probably gained her 'better than everyone' attitude because most of the spells she was taught were probably from that family member, and thus doesn't want to ruin their name by letting them be outdone.
 * This YouTube caption gives even more food for Epileptic Trees in connection with this WMG.

Trixie is a reincarnation of Nightmare Moon.
It's been said that something or someone caused Luna to become Nightmare Moon. Assuming that it's a thing, when the elements of Harmony purified Luna, the evil Nightmare Moon personality got separated from her. The elements can't outright destroy anything though (they either seem to seal you away or purge you of evil) The light magic from the elements diluted Nightmare Moon and gave her a new body. Memory-less, this new unicorn is an egotistical jerk due to the evil within her. Should she ever combine with pure darkness though, we might see a resurrection of Nightmare Moon.
 * So Trixie is the real Nyx?

Trixie will return, seeking redemption
Trixie wasn't all bad, but just too full of herself. In season 2, she will return seeking to amends, even if she doesn't realize it herself at first. And if Twilight ends up moving closer to being Celestia's heir, gaining wings or such, then Trixie would restore the original balance by replacing Twilight as one of the two unicorns in the Mane Cast.

If Trixie ever shows up again, it will be revealed that the Mane Cast does not remember her name.
Partly because it would be hilarious, and partly because it's the best way to annoy someone like Trixie. Oh, they'd remember who she is, they just won't be able to remember her name. ""I remember you! You're the show-off unicorn that nearly destroyed Ponyville with an Ursa Minor! The Great and Powerful Taffy!"

"Um, I think her name is Pixie."

"Naw, you're thinking 'bout that unicorn we met at Pinkie's party last week. Her name's Tracy."

"No, no, I'm quite sure there was an 'x' in there."

"Xavier?"

"No! It's…it's…Trixie! No, wait. That's not right…""

Trixie will defeat an Ursa Major.

 * (not OP) For inspiration on how, the Fanfic TrixCord gives a pretty good one: Trixie (albeit unwittingly empowered by Discord) uses an illusion to make herself look bigger than the Ursa and bluffs it.
 * Of course, it will happen just when there is nopony else around to actually witness her astounding feat.
 * And thus Trixie will miss the point entirely, thinking that actually beating the Ursa "doesn't count" unless she has witnesses.

Trixie has two older sisters, named Dixie and Pixie.
Trixie's parents were a pegasus and an earth pony; likewise, the eldest sister, Dixie, is an earth pony, while the middle sister, Pixie, is a pegasus. However, at least one parent was part unicorn, a trait that manifested in Trixie, much like Pound and Pumpkin cake were born of earth ponies.

Growing up was hard for Trixie; she was raised in a low class area (indeed, Dixie has a confederate flag cutie mark, and embodies the worst redneck traits), and her sisters mistreated her for being the odd pony out. Dixie was an outright bully, albeit slow-witted; Pixie was more clever and malicious, but fortunately had too short of an attention span to make the torment unbearable. It was being picked on like this that gave Trixie the cruel streak and the inferiority complex she now has, compelling her to one-up other ponies to prove her worth. When her powers developed, she used them to humble her sisters, before leaving home with the goal of becoming a famous magician. Once she was rich and successful, she could hold it over her siblings' heads forever. However, her misadventure in Poneyville was a harsh setback.

A future epsiode will have a defeated Trixie returning to the family home, where the older sisters will be introduced. News of her humiliation will have traveled ahead of her, and her sisters will begin mocking her for it. When Trixie challenges them to do better, they'll travel to Poneyville to antagonize the Mane 6; Trixie will have provided them with information regarding their abilities, using them as pawns in her plan for revenge. At first, their underhanded tactics will give them an edge, but they'll be defeated when Twilight notices their constant infighting, and tricks them with a ler's you and her fight ploy. While they're busy with each other, the Mane 6 will easily boot them out of town. The three will leave Poneyville, squabbling all the while.

Trixie took courses from Iron Will.
She too used to be timid and unassertive. And as with Fluttershy, Iron Will's methods worked just a little too well.
 * All but telegraphed in Trixie's speech cadence, stage presence, and liberal use of fireworks back in Boast Busters, all of which are staples of Iron Will's seminars. Girl is a dead wringer for her idol.

Trixie's suffering from a mild variant of Cutie Mark Failure Insanity Syndrome caused by a partial rejection of her talent.
Trixie's talent is item crafting. Her cutie mark is a wand. She travels in a nifty stage coach. Her fireworks are impressive. Her hat and cape practically make her character. And her Ursa story she's using a wand. However, Trixie has ambitions of being the greatest unicorn mage ever under her own power, something she can't do if she relies on focus items. So while she uses her items in the show, she has to beat any heckler under her own power to prove this to herself. The reason is is that she wants to be the Equestrian equivalent of James Bond, the mare on the field saving the day, rather than Q, the pony in the background who makes stuff for the cooler ponies.
 * Alternatively, her special talent is the use of magic, but not for practical purposes. Rather, it's magic for the sake of showmanship (her wand cutie mark is rather dramatic and flashy). The fireworks and such aren't gadgets she created; they come from her spells.

Trixie is a changeling.
In "Ponyville Confidential", Trixie is revealed to have a Dark Secret.

Trixie was one of Queen Chrysalis's disguises.
This one is self explanitory: They both have the same voice actor, both of them boast about doing very important things (Trixie defeating the Ursa Major, Chrysalis and her army taking over Equestria), and both of them are jerks. Kind of.

Trixie actually did defeat an Ursa Minor.
However, it was by accident and she knows that in the grand scheme of things, accidents don't count.

Discord cannot be defeated.
Because he is not evil, but a force of nature. Discord is the spirit of chaos and chaos is inherent to the world. Sealing him away was actually a huge mistake. Sure bad things happened, weather was stormy and animals were wild and unpredictable, but that's the way the world is supposed to be. Without him, the ponies had to take care of everything themselves and their world could no longer support itself without their intervention. His initial rampage at the beginning was because he was just so happy to finally be free he'd had so much energy pent up (and a little of it was just venting). Once he's amused himself, he will go about his own business, popping back every now and then to challenge the only ones he ever really had fun playing with.
 * Despite what Princess Celestia said, Discord does not equal Chaos. Harmony is the balance of Order and Chaos, as an absolute of either would be very bad indeed (A cold, logical world without fun, games or feelings without any kind of surprise, or a zany world where nothing makes sense). Discord, on the other hoof, means an imbalance, in his case, bringing more chaos than order, due to his crazy personality.

Discord's only real powers are deception and illusion.
Rarity's diamond is actually just a regular rock, the critters he uses to persuade Applejack with are basically just puppets. These are clues that all his other powers are little more than glamors and illusions: the crazy weather,the stuff with the animals, the unicorns and pegasi losing their horns and wings, but notice the earth ponies don't lose anything because they have nothing visible for his magic to act upon. And of course, the Elements of Harmony are still sitting there in the box, never having left. He merely waited for Celestia to move them to cast a concealment spell and then actually told the ponies that in his own riddling way: "...then find the elements back where you began."
 * Notice though, that Rainbow Dash actually falls when her wings disappear. If Discord can make objects intangible/undetectable for anyone else, then it doesn't really matter whether it's "real" or not. Same goes for all illusions, if they're perfect.

Discord has Hellish powers and may be the equivalent of My Little Pony Satan.
We already know Discord can manipulate ponies. In the released season 2 pic, where they're in a hallway, stained glass windows can be seen in the background. In one of them, we can see Discord as a puppeteer controlling the strings of an earth pony, a unicorn, and a pegasus. More interesting, though, is that the ponies appear to be hanging over a pit of FIRE, and they seem to be in incredible pain. (and if you listen closely when Celestia tells the Mane Cast about him, you can here ponies screaming in pain in the background) He may be the pony equivalent of Satan, a Hellish monster with dark powers that wants to make ponies miserable.

Discord is the Last of His Kind.
Considering how he has been labelled a Draconequus, rather than just Discord. This has implications that at one point, there were more than one of them. Whatever happened to the rest of them?
 * Either he's a unique mythical creature like the Pegasus was (Pegasus was originally the winged horse's name), or he murdered the hell out of the rest and took their powers.
 * Or there's more of them but the rest have no interest in screwing with things the way Discord does.

Discord is trying to test the mane cast, to see if they are ready for the real Big Bad
If they eventually pass the test and defeat him, good, that means they will be prepared for the Big Bad (And Discord probably has a backup plan to survive.) If they fail, then eternal chaos is a light punishment compared to what the true Big Bad will do to Equestria...

Discord's powers will revolve around The Power of Hate
Discord is, by virtue of meaning, the opposite of harmony, thus he's already partly the antithesis of the heroes' source of power. Since this is a show were the heroes power literally runs on the Power of Friendship, what better foe than one whose powers are the result of the opposite of friendship? Hatred. Discord literally means "the strife between people" (one meaning). Maybe he's an Anthropomorphic Personification of it or something, but his powers could revolve around hatred. Maybe he'll try to breed hatred between the heroes and break apart their friendship so they can't use the Elements Of Harmony against him, but that backfires by making their friendship stronger than ever. For irony, perhaps his actions end up uniting all of Equestria against him and he has a Villainous Breakdown when he realizes that. A possible way to defeat him would be Forgiveness, he wants to be hated so he'll be stronger, having no hate towards him would weaken him enough for the Elements Of Harmony to be used to reseal him.
 * Alright, the rest is unconfirmed so far, but is confirmed.
 * The newest preview seemingly confirms that he does feed off discord, possibly in the form of strife between people, as
 * Perhaps his defeat will spark an Alas, Poor Villain situation?

The Elements of Harmony sealed away Discord for good
When Celestia and Luna originally used the Elements, it wasn't strong enough to seal him for good. His grandiose pose when we first saw him in stone suggests that he already knew that it would only be a matter of time before he returns to Equestria and wreak havoc. This is why he underestimated the mane six when they came together again with the Elements. He thought it would be just like last time and that he would just be taking another short break. However, when they fired the Rainbow of Light, he realized too late that this one would actually seal him away for good, thus when he returned to stone his pose and expression this time was that of pure shock.
 * Or, the first time, he had no idea what the elements were or that they could hurt him, so he had no reason to fear. The second time, he knew what he was in for.
 * Plus, it's possible that Celestian and Luna only had five of the elements instead of all six.
 * In the opening of Season 1 Episode 1, it shows all six, implying that Celestia used all six against Nightmare Moon.

Discord is color-blind.
He can only see different shades of grey.
 * Similarly, Spike is apparently the only one to notice the grey. If it represents a spell that he can sense but Twilight can't, that'd help explain why Twilight was unable to figure out what was happening in the maze. Otherwise, she'd be holding the Idiot Ball for not making a connection between "I'm fighting a god of chaos" and "suddenly my friends are both acting wildly out of character and looking blatantly different". And the writers wouldn't do such a thing, right?
 * This could be Fridge Brilliance as a fair amount of animals actually can't make out colors. Granted, the colorful nature of Equestria suggests that ponies are among those, but Discord has a goat's head...
 * Actually when Spike sees them, they are in second-level greyness. A huge jump from original colour to grey colour is a significant change. But, Twilight? What she notices first is level 1 grey, then before they go in the house, they turn into level 2 grey. Besides, in that time, Twilight has started to lose patience and just wanted to settle things as quickly as possible, while thinking that defeating Discord might restore everything back.
 * My point: Either Twilight might not notice since it is a slow progression of greyness to her(unlike what a huge jump Spike notices), or she did notice but then she hoped that if she defeated Discord quickly with that party (that she still thought that there was hope), she could restore them back.
 * Maybe she DID notice the grey, but she just didn't know how to deal with it or what to make of it.

Discord's personality-shift spells don't work on ponies who are already grey
So Pinky's sisters are perfectly safe. Her parents however...
 * What of Derpy? Or Dinky?
 * Dinky's purple, so we could count on her being okay if this theory turned out to be true.

Discord is an avatar of Nyarlathotep.
As a messenger of Azathoth, his ultimate goal is to bring Chaos to the universe. After taking out Humanity at some point, his attentions are now focused on ponies. Fortunately for them, the Elements of Harmony are able to shut him out so long as they are active.

Discord is incapable of accomplishing his ultimate goal, since his plan is unsound.
Alright, let's say that Discord manages to defeat, brainwash, and/or kill anyone who could be a threat to his plan. He then proceeds to create a world of perfect chaos, where every single thing is chaotic, disharmonized, and generally makes no sense. But in a world where nothing makes sense, everything makes sense. By creating a world of perfect disharmony, Discord will have created a world of perfect harmony. Discord has never had this pointed out to him, or gotten far enough in his plan to realize this on his own.

OK, I stole this idea from Eight Bit Theater, but I think it fits.
 * So if everything is chaos... nothing will be?
 * worked for Linkara too
 * In a world where nothing makes sense, there still isn't anything that makes sense. Perfect disharmony means no harmony, even on accident. Knowing that a situation will be unpredictable just means that you know that you won't be able to predict what will happen. If Discord imposed complete, total control over the world, it might become orderly to him, but he never tried for that level of control. Besides, his actions, especially his response to being defeated, showed that he wasn't trying to make the world truly chaotic, he was just using that as an excuse and theme for being a jerk to people.

Discord was created by humans.
Following from the WMG theories that Equestria is Earth after humans go extinct, Discord was created by the animosity and disharmony during the war that ended humanity. Either that, or Discord was created through ill-advised magic or science, and caused that war himself.
 * Well of course Discord was created by a human.

Discord was created by other Animals.
He was going to be their avatar of revenge against ponykind for living magical, lavish lifestyles. They took the best attributes of themselves and combined it into one being, but the resulting spell drove it wild and created Discord. He slaughtered and scattered the various tribes of animals that he was meant to represent and turned to ponies next. For a long time, Celestia was unable to stop him. She went on a soul-searching journey and found five Animals, remnants of the tribes that created discord. A Griffon of loyalty, a dragon of generosity, an antelope of kindness, a goat of laughter, and she was the element of honesty. But they were never friends, at least not to Celestia. She was young and hotheaded and only cared to save her people from Discord. She didn't realize how special these "animals" were to her until it was too late. They had defeated Discord, but Celestia lost what could have been her very best friends.

Discord is telling the truth when he says he doesn't turn ponies into stone, but it's not because he has standards.
From his perspective, turning people into stone is simply boring. Stone is static and unmoving, and cannot spread chaos on it's own, unlike Discord's other alterations. Discord doesn't hate the concept of Taken for Granite because he has standards. He hates it because he thinks he can come up with better ideas.
 * Oh God, you mean he's Hexadecimal? In addition to being Q?
 * Well, they both have a chaos motif.

Discord was trying to turn the Elements of Harmony into the Elements of Discord.
If the Elements of Harmony were simply a threat to his existence, Discord would've just made them vanish with a thought; but that would be too easy. Instead, he performed Mind Rape on these 6 ponies and waited. Discord's tricks would've facilitated a Face Heel Turn for each of them, souring the Elements the moment they'd use them. In fact, if the real Rainbow Dash had been there the first time rather than Spike, the Elements would've belonged to Discord, and the universe would've truly been at his disposal.

Discord was originally a statue
The Elements of Harmony's friend beam can't do anything to harm other creatures, that's why they could only send Nightmare moon to the moon, and later, return her back to normal. That said, it didn't petrify Discord; it only returned him to his original form. However, that means there are now two forces of evil out there that are liberated.

Discord was created by the ongoing disputes of the Gods.
Originally, there were many racial deities, but the ongoing feuds of how to run their respective lands led to conflict. Discord was born of those conflicts, and took the amalgamated forms of the other gods to mock them. Then he systematically purged the other gods (which is why we never hear of any Buffalo, Cow, Dog, Dragon, Griffon, etc gods during these worldwide crises) and even members of the Royal Pony Sisters extended family. That's why he ruled Equestria and not the world. He was trying to draw Celestia and Luna into open conflict with him where he could crush them. He didn't expect the Elements of Harmony though.

Discord's shuffling is the cause of Twilight Sparkle's freakout in Lesson Zero.
Stained Glass Discord dancing on the head of Stained Glass Twilight Sparkle messes with the head of the actual Twilight Sparkle, through a sort of voodoo doll effect. That's why her OCD kicks into mythical proportions during Lesson Zero - all a repercussion of Discord's mind-warp power.

Discord may have been defeated, but he's still an immediate threat.
The episode immediately after Discord's defeat, Twilight went crazy, and displayed some very Discord-like tendencies. My theory is that, even after Discord's physical body was turned to stone, some part of him remained, at least in Twilight if not the other Element-wielders. I believe this is also what happened to Luna/Nightmare Moon; after defeating Discord the first time, she was altered/possessed by Discord.

Discord is a genetically engineered being...
... Just like Luna and Celestia. Thousands of years ago, some scientists (were they pony? Were they human? Or something else? WE MAY NEVER KNOW) strived to create the "perfect being". Luna and Celestia were far from the only creations, but they were the most successful. Discord was initially declared a success, but since he's made up of so many different creatures, he had a mixed-up nature that made him crazy. (similar to how if you breed dogs from two different breed classes, they're often conflicted on their behavior) He easily broke out of the facility, killed the scientists, and took over the world. After a while, Luna and Celestia stood up to him. The reason they didn't kill him was pity, they knew it wasn't his fault he was so messed up. They intended to find something that could help him so he wouldn't have to stay stone forever, but their responsibilities to the rest of the world just kept getting in the way, not to mention the Nightmare Moon fiasco which made it even harder for Celestia to work on many things at once. It's one reason Celestia set up the institute of magic, as she hopes that one day, maybe another unicorn will find something to help him.

Discord is actually just another victim.
He was never evil to begin with, or a Draconequus, just an alicorn prankster. Like Pinkie Pie, however, he knew when a prank would be too much. However, one day, while he was up rearranging the stars (probably into some juvenile statement), he was attacked by some dark force that wormed its way inside him.

Though the attack seemed to have no effect at first, his pranks eventually started to get more vicious. Then he decided that it didn't matter if anyone else laughed, as long as he got a laugh. He went around, sewing chaos everywhere, and drawing power from the conflicts he caused. The dark force fed off this power, making Discord more malicious. As he grew more malicious, he caused even greater chaos to draw power from. A negative feed-back loop was formed. The dark force eventually began affecting his physical form, gradually twisting him into the monster we know him as now.

By the time the other alicorns figured out what had happened, he was too powerful for them to stop. He proceeded to wipe the alicorn civilization from the planet, until six young alicorns discovered the Elements of Harmony. By the time they engaged Discord with their new found power, the darkness in him was too powerful to be purged, but they managed to seal him in stone. During the battle, four of the six were fatally wounded, and during the sealing, a small portion of the darkness broke away and took up orbit around the moon. The two remaining alicorns, Celestia and Luna, last of their kind, preceded to rebuild civilization using the lesser pony races: earth, pegasus, and unicorn (and sea?).

The darkness eventually returned and attacked Luna, but Celestia, having seen the signs of corruption in Discord (particularly the first physical manifestation, those draconic eyes), banished her sister to the moon, isolating her from any source of power for the darkness to feed on, and giving her time to find new bearers for the Elements of Harmony. Since the darkness in Luna wasn't nearly as strong as it had been in Discord, Luna could be purified, but if she had been allowed to corrupt more thoroughly, her form would have also twisted, though retaining a lunar them, as opposed to Discords chaotic theme.
 * If the Elements of Harmony alone weren't powerful enough to purify Discord, perhaps adding more 'good' elements will help?
 * Like Charity, Chastity, Diligence, Humility, Patience, Temperance, Courage, Love, Sincerity, Purity, Hope, Light, Miracles, Determination, Hard Work, Honor, Responsibility, Resourcefulness, Selflessness, Valor , etc. SURE!

There are cultists of Discord.
Because every Evil God needs a group of complete lunatics thinking he's the best thing ever. Surely there must be some cultists of Discord as well, worshiping him and maybe even making sacrifices to him in order to give him the strength to break out of his stone prison. Some of those would be sadists and masochists who revel in pain and suffering, and some others might simply be complete loonies (a bit like Pinkie Pie) who are simply into all the random events Discord can make happen, like the chocolate rain clouds. Possibly one of the later villains could be one of them or a whole group of them.
 * This troper has noticed three ponies that just may be contenders for that position: they're nameless background ponies who each have flower-themed cutie marks (seen here), and are often the first to freak out when some huge chaotic thing happens in Ponyville. But their freak-outs are actually their own way of praising their master--what better way to pray to a chaos spirit than with uncontrolled screaming and hollering?
 * Seriously, you not talking about "The Flower Trio", aren't you?!
 * I support this if keepers of the "Elements of Discord" are involved.
 * This Troper had fan ponies with Discordian cutie marks before the character Discord appeared... when he showed up they were uqickly reworked to be Discord cultists. I'm glad others have this idea, too.

Discord is a much more sympathetic and tragic character than most people think.
When Celestia and Luna were fillies, and playing with their magic, they accidentally merged many beings into one. The result was a strange-looking anamoly in reality. The resulting person was driven insane by all that had happened to him. As a result, he wants to create mayhem and suffering, either because he genuinely believes it's the right thing to do or to try to end his pain.

Discord was driven mad by the "normal" world.
Think this through. If Discord is chaos personified, imagine how mind-raping the "normal" world must be for him. With all the organization and structure of the world, he should react the way we do to Eldritch Locations (i.e. getting mentally screwed over). The world drove Discord insane (by his standards), which is why he makes as much sense as he does, much the same way that Eldritch Locations bring their disorder to our minds. After all, his Evil Plan to destroy the mane cast's friendship required planning, structure, and, most importantly, order.

Discord was originally a Chaotic Neutral Spirit Of Chaos.
Discord was originally the true spirit of Chaos, as in the balance between chaos and order. He was meant to provide the chaos needed to get the world to work as it needed to. However, eventually, he began to question why he needed to hold back on his fun just to work in harmony with the rest of the world when he had the power to do whatever he wanted to, and decided to do just that, turning Chaotic Evil. He then proceeded to conquer Equestria and turn it into his World of Chaos. It was at this point he was dubbed the Spirit Of Disharmony, as he'd gone from an entity filling it's proper place in the world to one destroying everything For the Evulz and disrupting harmony. With his defeat, the world no longer had him to provide the chaos to power nature (thus why the ponies have to do everything), but Celestia promotes enough Chaotic Good in her subjects to counterbalance his absence on a social level. Alternatively, Pinkie Pie is his replacement and doesn't know it.

Discord literally could do nothing once the Elements were activated.
The Elements represent harmony, while Discord represents disharmony. And yet the Elements have proved to be more powerful than him on two occasions. When they're actually activated, their power exceeds his own. For the same reason Celestia and Luna couldn't take control of the moon and sun from him once he'd messed with him, he can't effect or counter the Elements with his Reality Warping powers because they're stronger than he is.

Discord and Nightmare Moon will be expies of Esmè and Olaf.
And yes, they ARE dating!
 * We haven't seen the guy yet and shipping is already happening!
 * We have now, although the shipping thing, I'm not sure.

The vision Discord showed Rainbow Dash of Cloudsdale will come true.
Cloudsdale will crumble, but it will be because of a different villain. Perhaps in the next two-parter.

Celestia and Discord will turn out to have been lovers before he was imprisoned.
And even in the present there will be tons of Foe Yay.

Discord will return as a less menacing recurring villain.
Don't take this the wrong way, I don't think it's a good idea to make him Lighter and Softer for the sake of having him stick around more permanently. That said, the writers have created an amazing character and it would be a shame to let him go after just two episodes. He may escape once again, but perhaps tone down the craziness a little, if only to avoid being imprisoned in stone again. "Twilight: Discord! You've unleashed your chaos upon Equestria once before, and we won't let you do it again!

Discord: Oh, what a poor first impression I must have made! I admit it - I overdid it a little back then. It's just that I hadn't seen any proper chaos in such a long time! Anyway, I've had a lot of time to think--one tends to have a lot of time on their hands when they're frozen in place--and I realized that neither of us are going to get what we want if I keep messing everything up!

Twilight: None of this matters to you, Discord! We're putting you back where you belong!

Discord: Oh, haha! How cute. No--you see, you never had a choice. As I mentioned, I've had some time to think, and I've learned from my mistakes. You won't be getting one over on me this time, Twilight.

Twilight: Grr! Stop stalling! Come on, girls! *prepares friend beam*

Discord: Forgive me! Here I was, thinking I was being a good neighbor and warning you. Toodles! *teleports*


 * beat*

Pinkie Pie: *gasp* Does this mean we get chocolate rain again?"


 * And the Mariachi ponies are where?
 * On a time-travelling spaceship, collecting souls for pony-Satan.

kill him. Either with the fires of friendship or some other way since its clear that turning him to stone doesn't work and unlike Luna, He can't be redeemed in any way.

Any image of Discord can become Discord.
Like the Weeping Angels of Doctor Who, Discord can spontaneously arise from any depiction of him. The original spell that Celestia and Luna cast using the Elements of Harmony over a thousand years ago didn't turn him to stone as such, it suppressed this effect, so that when they destroyed his current incarnation, he stayed dead until the spell wore off at the start of Season 2. The statue of Discord in the Canterlot statue garden was literally just a statue until it became Discord himself. He didn't mess with the stained glass windows in Canterlot Tower - the depiction of him in one of the windows animated and became him, stuck in the windows. Celestia didn't destroy the statue and the windows because no matter how much damage Discord could do if he materialized in Equestria, it would be worse if he materialized inside Celestia's memory.

Discord was created/magically elevated to combat an entity embodying Order.
Ancient Equestria was once ruled by a tyrannical figure, whose rigid laws imposed divisions and hierarchy among ponies. His extreme, draconian rule led to the unicorns/alicorns powering/making Discord to counteract it. The Draconequus' chaotic abilities eventually drove the entity away, freeing the populace, but without any real opposition Discord's chaotic tendencies soon took over and he began to subject all of Equestria to his cruel whims. The Elements of Harmony were thus created by Celestia and Luna not only to defeat Discord, but also to embody a unifying force that was neither order nor chaos.

Discord was created/magically elevated by the Elements of Harmony.
The Elements of Harmony work in strange ways. In this case, Discord was fashioned in a time when Equestria threatened to be torn apart. Civil unrest, wars from outside, famines, freezing winters, scalding summers, plagues, monsters, volcanoes, earthquakes... all of these were ceased, and their chaotic energies were combined into a single entity. Why? So the Royal Princesses (or, perhaps, more ancient wielders of the Elements) could banish discord from Equestria. Naturally, there was some time limit, and he was turned to stone upon returning.

Discord is the brother of Celestia and Luna.
The three had been created one at a time to rule Equestia together, but each had to be raised as a child and go to a school to learn how to rule before they could do it, Discord was grown up long before Celestia, who didn't want to rule until Luna was grown up. He then began to rule on his own, and because he was the spirit of chaos he caused a horrible Crapsack World due to the lack of the harmony his sisters were supposed to control. When both sisters were grown up, they thought he was causing so much unredeemable chaos that instead of learning to rule together as they were meant to they turned him to stone to get rid of the chaos altogether. Celestia was so ashamed of him that she refused to mention that he was her brother, and he was so secretly mad at her that he didn't bother to mention she was his sister. It is because of his sociopathic chaos causing nature that he was somehow a mismatch mutation instead of an Alicorn, it's also possible he altered his own appearance so no one would assume he was related to the Alicorn sisters. Word of God said the sisters have no other siblings, but it makes sense for Celestia to want to deny being related to Discord.

This comic is true.
Because if it is, that means Discord is coming back. Squee!
 * Alternatively, this comic is true. That said, it would still mean the same thing, but still.

Remember that throne Discord had?
That's Twilight's chair. It is a chair that is near and dear to her heart. Therefore, Twilight wants Discord to get out of her chair.

The Cutie Pox was Discord's doing.
The paleo-pony period could be the time where Discord's reign happened, so it could be possible.

The Windigos were Discord's minions.
Beings that feed off of hatred and drove wedges between the three tribes? What better minions for a being personifying Disharmony? Either he was pulling the strings behind the scenes and arrived shortly after Equestria's founding and conquered it or they were remnants of his rules that survived his downfall.

Discord isn't really a Draconequus.
There's probably a race out there called "draconequus" (Mix and Match Critters, or perhaps just look like it), but Discord isn't a member. He probably just looks like a draconequus, and the ancient ponies didn't know better; or, he claimed to be a draconequus to obfuscate his true nature as a Spirit of Chaos and Disharmony.

To add to the above: Discord does not have a "true" form.
I read on the Princess WMG a theory that the princesses only manifest into the form of ponies for convenience's sake. Discord seems to be either on par, or more powerful than them, so it stands to reason that he is very similar. I propose that the Draconequus is a mythical race found in old pony tales (just because you live in a world made of magic, doesn't mean there are no still mythological beasts) that a formless chaos being found out about. He knew the form frightened ponies (if he was being serious), or was hilarious to them (if he was being ironic). So, the once formless chaos being created a physical form similar to the being found in pony mythology, and made it a new, horrifying, reality.

Discord knew Celestia growing up.
We do not know how old Celestia/Luna are, but they are old enough so that their actions can enter the realm of folk culture. After all, wouldn't the ponies remember if Nightmare Moon was going to bring eternal night if it had happened within their parent's lifetimes? Rather than have characters like Spike speculating on whether or not it's an 'old ponies tale'? So obviously both Celestia and her sister are significantly old. Discord never specifies how old he is, save the 'eons' comment he makes. Eons are typically indefinite large periods of time, and even then, they are often used colloquially in speech. Celestia also makes no comment about Discord usurping power from her, only her and Luna defeating him, and then (presumably) coming to power. We can assume that Celestia wasn't in power then because she was too young.

With that established, we can speculate on what their relationship was. Perhaps This video is true. Maybe Discord was a social outcast isolated by his physical appearance (perceived as a deformed pony, even? Since that's how his statue was described), and only befriended by Celestia. His reign of terror could be attributed to his own weird 'chaos' morality and a desire to 'get back' at the ponies that were cruel to him.

Discord is Fegelein.
FEGELEIN! FEGELEIN! FEGELEIN!

You think Discord's outward appearance was strange?
Chances are that his insides make even less sense. Including, but not limited too:
 * Instead of vertebrae bones, he has an exoskeleton, and a cuttlebone.
 * Seven and a half kidneys. In his head where his brain is supposed to be.
 * A digestive tract that loops several times in a mobius strip despite being a tube.
 * Platypus Spurs, behind his ears.
 * A magnetic tail so if you're made of metal, he can latch onto you.
 * An extra pair of eyebrows, That only appear on Saturdays.
 * An appendix that's larger then his stomach. Still useless.
 * A pancreas that acts as a black hole.
 * And above all: No Heart.

Tom Dan really was a diamond...
...enchanted so that everypony but Rarity would see it as a rock.

Wouldn't it have made so much more sense to give Rarity a rock and brainwash her to perceive it as a diamond? Yes. But what fun is there in making sense?

Discord's defeat by Celestia
Equestria is apparently older than both Celestia and Luna, and before then the unicorns controlled the heavens. Equestria is still hyper ordered back then, too ordered for ponies to live without cooperating, so if Discord is the spirit of natural chaos it means he was sealed away even before the founding of Equestria. Discord must have come from somewhere, and sense he is so powerful and immortal it makes more sense for him to be as old as time itself than being created sometime after the founding of Equestria.

The prince's love poison was supplied by Discord
The story says "something about a dragon", "chaos reigned", and "a kingdom collapsed". After his creation/arrival/, his first act were to disable to the royalty so the kingdom by giving the prince the love poison (maybe as part of a Deal With the Devil) would descend into chaos, the perfect opportunity for him to seize the throne.
 * Going further, while under the influence of the love poison, the two of them had a pair of daughters. Because of their parents' lack of interest in anything other than each other, the older daughter become a chronic workaholic to compensate for their poor governance, while the younger grew up to be eternally starved for affection. No wonder Celestia was so pissed off when she saw him.

Discord breaking free of his stone confinment was because the CMC where fighting so close to him
It doesnt really seem like there would normally be much fighting in the canterlot garden, so it must be proximity based

The reason why Discord corrupted Fluttershy telepathically?
He didn't simply choose to corrupt her that way after using mundane methods on the rest of the ponies - Fluttershy is just too nice to be corrupted without supernatural means, so Discord just used his magic.

Discord is from Taurtarus.
In the episode "It's About Time", Cerberus appears and Twilight informs that he is the guardian of Tartarus, which is apparently where a bunch of evil creatures are sealed. In Greek mythology, where he comes from, Cerberus guards Hades, which can be viewed as an equivalent to Hell in some aspects. Discord was one of the evil creatures sealed in Tartarus, but he grew very powerful and managed to escape. He was too powerful to be put back so he was turned to stone.

If Discord comes back in Season 3, he'll be redesigned.
He'll have body parts from Season 2 antagonists, like maybe:
 * Adult!Spike's right leg.
 * The left leg of the timber wolves.
 * The right arm of the wendigos.
 * Flim and Flam's shirt and hat.
 * Ahuizotl's tail.
 * Iron Will's left arm and/or right horn
 * The left wing of the leader of the teenage dragons.
 * Queen Crysalis's right wing and/or left horn.

Discord is Q.

 * Physical God, check. Trickster Spirit, check. Creates chaos For the Lulz, check. Screws with peoples' minds for fun and profit, check. Played by John De Lancie, check. Take Q, hop a few dimensions and add a new body (which must have been fun to make) and you have Discord.
 * Also in "Return to Harmony part 1" he said his favorite element is Laughter (who is pinkie) while in one episode of Star Trek: The Next Generation in the episode "Deja Q" Q gives Data a "going away" present, what was the gift? Laughter.
 * Alternatively, he could be a Mirror Universe counterpart to Q.

Discord has permanently corrupted the cast.
We've seen most of the characters have at least one major freak out in season 2, often outright acting like they did under Discord's control. I think that he has driven them all permanently mad, and that they'll slowly grow madder and madder with time. Twilight in Lesson Zero, outright losing her mind. To a lesser degree in It's About Time. Fluttershy in Putting Your Hoof Down, acting almost identical to how she did under Discord's influence. Rarity in Sweet&Elite, ignoring her friends for material gain. Applejack in The Last Round Up, running away and lying to all of the others. Rainbow Dash in Mare Do Well, Not to mention the rather OOC actions of the rest.
 * Pinkie hasn't had a significant freak out yet, but we know she's already prone to flipping, like in Party Of One.

Discord is a genetic creation by the Umgah.
I came up with this theory because Well, look at him, he looks like something the Umgah would make! I think that the Umgah created him to do havoc on planet of Equestria as a practical joke and while Discord was doing his Chaos the first time, you can bet those blobies were laughing so hard!

Discord and Celestia were once best friends.
But, at some point, something happened to him and he became corrupted, possibly through magical means. Celestia didn't have the heart to kill him so she had him turned to stone, with the slim hope that someday, she can find a way to restore him to his good old self again.

Discord turns to stone if there's no Disharmony for him to feed on.
He was freed thanks to Disharmony happening right in front of him and got progressively stronger as things progressed, or at least seemed to. He draws his power from Disharmony and blasting him with the Elements of Harmony is blasting him with the antithesis of his own power, draining it all from him.
 * Optional WMG: If he returns, he won't be beaten with the Elements, but instead by the mane cast managing to starve him of Disharmony somehow.

Discord is a corrupted Star Swirl the Bearded
Similar to the above genetic engineering WMG, to further test the limits of magic, Star Swirl dabbled in experiments outside of public view. His last experiment was to turn himself into the perfect being, giving him the magic, strength, and speed of some of the best animals in Equestria while still not completely changing his physical appearance (Summoning his wings when he wanted to fly, for example). Unfortunately, the experiment went out of control and turned him into the draconequus we all know and love. Upon his transformation, Star Swirl believed that he can further his studies despite his form to test the limits of the world, but felt that the harmony between ponies was getting in his way, so he sought to inject chaos into the world. Over time, his mind deteriorated and, in the end, lost sight of his original goal, becoming more focused on chaos and disharmony, eventually adopting the name Discord. However, because he kept his more unethical experiments to himself, everypony assumed he had died when Discord appeared and because his publicly distributed studies helped further develop unicorn magic, his name tends to be more fondly remembered.

Discord never was an actual "spirit of chaos" to begin with.
He was simply lying about that all along to make himself sound that much more impressive and important. He's really just a super-powerful Jerkass of unknown origin who has no actual essential function in the setting; the whole "chaos" thing is at least in part merely an act to mess with the usually order-loving ponies' minds.

Discord's species may have a very different language of that the ponies. If ponies represent Western Europeans, then Discord's race may represent Asians as Discord looks very much like an Eastern Dragon. Perhaps in Discord's kind language they call themselves longs (chinese word for Dragon)