Avatar: The Last Airbender - The Promise/WMG

== Suki will dump Sokka for someone else or vice versa, leading to a lot of tension. In the end, an angry Suki and Kyoshi warriors will learn the Chi Blocking techniques from Ty Lee which will somehow be passed on to the predecessors of the Equalists. == Sorry to sound like I'm writing in the middle of a sleepwalk, but right now I can't think of any other person who could teach the art. And I'm making the guess out of what Korra saw in her flashbacks - this whole thing might have had something to do with Sokka falling out with Suki and the Kyoshi warriors.
 * The first part may have some probability greater than zero.

The Trolling Creators have never given a thought about Zuko's mom at all until now. We will never find out what happened to Ursa.
Face it, we are not going to know Ursa's fate in the Promise at all, or maybe never. Ozai will talk everything but that. Why? Because even Mike and Bryan don't know, and they want to have fun. If Ursa's fate hasn't been resolved by Korra's time (read Episode 1), then the fans will not get their answer.

Zuko is actually planning a Batman Gambit that will make his his father an Unwitting Pawn and reveal where his mother is.
Think about it. Gene Young is said to have been collaborating with Bryke, who are far too awesome to allow him to murder Zuko's character development like this. Him being torn between his nation and the world, I can get. (This may just be a part of his plot, too, but I dunno.) But asking Ozai for advice? Right after having a bad dream? And bringing tea and bowing his head, after his supreme Calling the Old Man Out? I don't buy it. I think Zuko was having a bad dream about his mother, and remembering their previous conversation where Ozai mentioned the advice and tea and 'maybe even mentioning something about your mother', decided to try and pull off a Batman Gambit to convince his dad that he could be used by him as an Unwitting Pawn, while actually using his father as an Unwitting Pawn and sneaking out his mother's location out of him. Zuko is not carrying the Idiot Ball- he's just being aWell Intentioned Mamma's Boy.

Toph opened her metalbending academy in Yu Dao because of its reputation for good metalwork and for oppression.
Someone, perhaps Iroh as a way to keep someone handy in a politically tough area, pointed Toph towards Yu Dao colony as a good spot for her academy. Why? First, Yu Dao has a reputation for hosting the world's best metal smiths. It's very Toph to storm the stronghold of the industry and declare "I'm gonna work metal better than all y'all!"

Second, most earthbenders are either second-class citizens or outright non-citizens depending on their ancestry. Unless they have the benefit of a 1) marrying up in the world, 2) or being lucky to be born with at least one FN parent, they're decidedly underclass. That means Toph has a pool of tons of potential earthbending students, many of whom will be versed in the local industry of metal work, and who'll be hungry to do better for themselves and their families by learning a lucrative trade in metalbending. The locals who want to be her students won't be in it for kicks. This also explains why Toph's so quickly hops on the "kill Zuko" bandwagon. When he announces the Fire Nation's intention to keep its remaining colonies, Toph knows that the status quo means her students will face oppression at home for the rest of their lives.

Sokka will come up with the name for Republic City and the United Republic of Nations.
The way Toph lampshaded the way he came up with the name for the Harmony Restoration Movement totally set up Sokka's skill for naming things as a Brick Joke.

Kuei's adventures in Season 3 will be shown in flashback.
While Zuko had his chance to talk about the human cost of evacuating the colonies in Volume 1, Kuei will get his chance to do the same about not evacuating the colonies in Volume 2. He'll relate the story of how he got to know war refugees during his wanderings with Bosco in Season 3, and how only the Harmony Restoration Movement can help them resettle in lands that they or their parents lost during the war.

Iroh will oppose Zuko on the colonial issue.
Iroh's position will be that Zuko needs to make the tough call and evacuate the colonies as a necessary step for a lasting international peace. This will force Zuko to step more into his own as Fire Lord as he has to honorably disagree with his Uncle.

Zuko's showdown with his allies over the colonies, and the ensuing creation of the United Republic, will win him major kudos in the Fire Nation.
By standing up to the Avatar and the Earth King, as well breaking with his Uncle Iroh's policy position on giving up the colonies (see above), Zuko will prove himself to not be a puppet of foreign influences. While he'll be giving up land that once belonged by hook and crook to the Fire Nation, the pluses will greatly outweigh that minus in the Fire Nation people's eyes. Why? Because they'll have less former colonials moving back to the Fire Nation proper, taking away jobs from natives and driving down wages, and there won't be an influx of mixed race children like Kori who are technically legal citizens even if they're earthbenders. More pleasingly, the Earth Kingdom won't have its former territory back. The United Republic of Nations will be an independent nation, certainly, but in its early years, before there's an influx of new settlers, it'll still be culturally and economically tied to the Fire Nation.

Eventually, someone will bring up the possibility of Aang using Energybending on Zuko.
After all, it worked on Ozai, why not his son? Well, turns out there's a very good reason why that won't work. Aang needs to have a stronger will then his target in order for Energybending to work. Unlike his father, Zuko is a Determinator. If Aang tries it, it will end badly for him. This will either be shot down with the above expanation, or Aang will try it out and learn why this is a bad idea the hard way.

Yu Dao will become Republic City.
A bit of an obvious one, but it's the longest established colony, there's already some integration between nations, it's one of the wealthier settlements, it has a port city. It has all the indications that this is where the United Republic begins.

Kuei is trying to stir up a Fire Nation civil war.
Kuei, sore from all that business with Long Feng, wants to have the Earth Kingdom restored to its proper place under the sun, and he thinks that can't happen until the Fire Nation is no longer a threat. So he uses the Harmony Restoration Movement to get Zuko to ethnically cleanse the colonies, something that would certainly spark a second war if the Earth Kingdom was the one doing it, but this was Zuko is the one taking the heat. If the Fire Lord doesn't get overthrown, that's still good, as all those former colonists will lower wages and raise food prices back in the Fire Nation, undermining Zuko. Plus, Kuei would then have a Fire-free northwestern seaboard. If the Fire Lord is deposed, then the Avatar, enraged over his friend's death, will force the Fire Nation back into compliance with the peace treaty, maybe even with harsher terms this time since Aang generally frowns on death as a punishment. If the Fire Lord turns his back on the Harmony Restoration Movement, as has happened, then Kuei hopes the Avatar will see that there aren't even any "good Fire Nationals" that he can ever trust, thereafter placing the Earth Kingdom in a better diplomatic position (with the Avatar) against the Fire Nation in any future conflicts.

Iroh is a willing hostage of Ba Sing Se, so Zuko can't consult with him about all this stuff he's going through.
Iroh offered himself up to the Earth Kingdom, which has always wanted to put the Dragon of the West in the slammer, as a hostage in order to secure a quick peace treaty. So long as Fire Lord Zuko sticks to the terms and conditions of their mutually agreed upon peace treaty, Iroh will be allowed to whittle his days away in house arrest at the Jasmine Dragon, selling tea and rubbing elbows with the city's elite, only putting up with imposition of his mail being monitored. If Zuko breaks with the treaty, like now... well...

Aang is the only member of Team Avatar who still thinks of Zuko as a friend.
The head-scratching ease with which Katara, Sokka, and Toph all seem to presume the worst about Zuko makes more sense if he's not their friend. Comrade-in-arms? Absolutely. He fought alongside them, even took a big hit for Katara's sake. But friend? Well... not exactly. Toph and the Water Tribe siblings come from cultures that have spent the last one hundred years fighting against Fire Nation aggression, and moreover Zuko hasn't exactly proven himself to be steadfast in his alliances. Once a traitor, always a traitor; and Zuko committed treason against both side in the Hundred Years' War. Between his shifting loyalty, a touch of racism towards Fire Nation folks, and the last year where they haven't been spending time around him, Zuko fell out of favor with Toph and the Water Tribe siblings. Whatever friendship they had during those few weeks at the end of Season 3 has wasted away.

Aang is different. Not just in how he's open with his heart, but in the fact he comes from an era where there wasn't a global predisposition to loathe the Fire Nation. Aang doesn't think of the Fire Nation as being any different from the other nations. Plus he's been amazingly amicable about the whole genocide thing. So when Zuko became a friend to Team Avatar in Season 3, that meant he became a friend to Aang for life. That's why Aang is the least kill-crazy of his friends, and why it's not until Zuko hits his Berserk Button about Katara that he ever hints at making good on his promise.

We will get an explanation as to how Boomerang came back into Sokka's possession.
Yeah, we're all glad that Boomerang always comes back... but how did it come back this time? What about Space Sword?
 * He made or bought a new one? It's not that hard to come by a boomerang. The Space Sword is another matter.

Aang will go all out into Avatar State ass kicking when Zuko and Kuei go for war, not willing to talk. All that is going to leave a bad impression on the non-benders
What else has enough power to stop two armies of two entire nations in their tracks? The way things are going, it's clear that tensions are high and both Zuko and Kuei will refuse Aang's proposal for talks, each using the With Us or Against Us argument. All that over and above the conflict between Yu Dao's citizens and the Freedom fighters. We're going to see some epic bending coming up as Aang decides to crack the whip.

The non-benders caught in the middle of all this are going to have some serious grudges against bending.

Spoiler warning for part 2. Kuei will question his stance after seeing earthbenders working with firebenders to protect Yu Dao from his army.
Because it would be a great pay off for the scene we get of Kori practicing with her earthbending and firebending cousins. And this will bring Kuei to a point where he's willing to work something else out.