Assassin's Creed III/WMG

A spin-off will involve Connor matching wits with Napoleon Bonaparte
We know that Napoleon had a Piece of Eden in his possession at some point, so it's likely that he was a Templar. Even if he wasn't, he's just too juicy a character to not be involved in the Assassin's Creed saga in some way. And as dictator of France, he was known for having an extensive network of spies around Europe, which would be a good environment for an assassin to work his magic. And since the events of ACIII seem to be focused around America during the Revolution, it would make sense to have a follow-up set during the Napoleonic Wars (possibly even the War of 1812), where Connor could see the events of the Templar-Assassin struggle on an international scale and get a look at its effect on the dynasties of Western Europe.
 * And as a side note: we know that Napoleon was involved in a long campaign in Egypt around 1799, right? Wasn't one of the Pieces of Eden hidden in Egypt for a few thousand years...?

Connor will be unrelated to Ezio directly and will end up marrying Ezio's female descendant
Another case of the bloodlines gathering together to eventually end up on Desmond. Likewise it's unlikely that he's directly related to Altaïr either.

Connor Won't Have Eagle Vision/Sense
During a certain part in Revelations, William says that. From this, we could infer that Ezio and Altair are Desmond's paternal ancestors. Now, Connor's gameplay has been described as being more like a "predator." Being half Native American and having grown up hunting for food, maybe he has honed his tracking and hunting skills so keenly that Eagle Vision/Sense would be of no use to him in finding his targets. This would make a great reason for him to come from William's bloodline, rather than Desmond's mother's.
 * If this is true then perhaps Bill could take his turn in the animus, which would give Desmond a little more freedom. Eagle Sense is an established gameplay mechanic though, so Connor might have 'Hunter's Sense' or something similar which functions close to the same.
 * I thought that William's comment of The indication is that Desmond's FCG are coming down both his maternal and paternal lines.
 * Sort of confirmed by Word of God, that says that Ezio and Altair are not related.
 * While true there's also the possibility that their descendants married and their line produced Desmond's mother or father.
 * Given the apparent wolf motif of Connor, rather than the Eagle motif of Ezio and Altaïr, perhaps the "Eagle Vision", something sight-based, is replaced with a wolf-themed sense built around scent. Could make things more interesting if targets picked up on this fact and used water to throw off the trail, making them harder to identify (at least, by smell).
 * The "Design and Combat Interview" had one of the developers saying they redeworked the triangle button (presumably the one from PS 3 controolers, which is the eagle vision button) to give the ability to switch tools while fighting. The Eagle sense wasn´t used or even mentioned in the demos, too.
 * Jossed, Connor does indeed have Eagle Vision.

Who's a Templar during this period
Lot's of interesting choices to pick from in this time period. Let's get the ball rolling:
 * King George III: Not all Brits will be evil, but the king himself seems ripe for a Big Bad role.
 * Benedict Arnold: A chance for Ubisoft to play with Betrayal Tropes. This could also set up a possibility for Arnold to be assassinated during an attempt on Washington's life, similar to the mission where Ezio defends Prince Suleiman in Assassin's Creed Revelations.
 * Alexander Hamilton: He was actually conspiring with Aaron Burr, but Connor ends up offing them both.
 * Sam Adams: his actions with the Sons of Liberty were definitely Templar-ish.
 * Charles Lee: One of the screenshots shows Connor lunging at him.
 * Some of the Founding Fathers. The American government is built on philosophies that resemble a loose mix of those of the Assassins and Templars as described in the games, so it would make sense that the new nation was an attempt to an armistice of some sort.
 * Which is Truth in Television, since a pretty good number of the Founding Fathers were Freemasons in Real Life.
 * George Washington. According to 16, he did get his hands on Apple and pass it down through the Presidency, where various people used it to control the people. That's a pretty Templar-ish thing to do. Given that Connor seems to be friends with him, the reveal will probably come as quite a Player Punch.
 * The revelation about the mentor being the villain was done in the first game. Plus, would Ubisoft be brave enough to make one of America's Greatest Heroes a bad guy? It would make for a better twist, but still...
 * Napoleon Bonaparte: He's not directly linked to the American Revolution, but he becomes a shifty ally of the US around the time of Jefferson's presidency, he tried to found a global empire that he thought would last for thousands of years, and we know from one of the in-game puzzles that he possessed a Piece of Eden at some point.
 * Marquis de Lafayette: He was one of the key players in the American and French revolutions, and he was instrumental in America's victory against Britain. His noble background gives him access to the kind of wealth and power that you'd expect from a Templar, and he was a major opponent of Napoleon, possibly indicating an internal dispute within the Templars. If they do make a spin-off featuring Napoleon in a major role (see above WMG) it's likely that he'd have a big part in it, since he'd serve as a bridge between the American Revolution and Nappy Bones' rise to power in France.
 * Marquis de Sade: Because video-games need Fan Service, dammit!

La Volpe will make an appearance
... as Francis Marion, the Swamp Fox. The partisan's style of combat fits the Assassins, striking quickly and than disappearing. And Marion's men attacked mainly supply convoys, that would be fitting for a thief.
 * La Volpe will have been dead for a couple hundred years by the time of this game. Not to say he couldn't have had any descendants who could appear, but no La Volpe himself.
 * Or counter point. La Volpe is a title passed down from generation to generation and a La Volpe will make an appearance.
 * OP phrased herself badly- she meant on the off chance the rumors of him being immortal were true.

Connor discovers the vault by the end of the game.
Revelations reveals that the Vault is located in upstate New York. Seeing as how New York is one of the locations in the game, this probably sets up a quest to stop the Templars in finding the Central Vault. He might end up discovering the very secret that the Assassins need to prevent mankind's extinction.

The game will probably be the last game to be set in the Animus.
The next game will feature Desmond as the main hero who will save the world from a large solar flare.
 * Though there is the problem of ACIII being confirmed to end Desmond's story.
 * Downer Ending anyone?

Connor won't be the only ancestor we visit in this game, but he will be the 'main' one.
Ubisoft have stated that Desmond will attempt to save the world by "visiting the memories of one (or more) ancestors". Therefore, there will probably be a few sequences in which we visit other ancestors. Since Desmond has thus far been used to find Pieces of Eden, the other ancestors will be those who have found other PO Es relatively early in their lives (compared to Ezio at least) and therefore won't need so much synch to access the POE memories. Connor's story is stated to take place over a span of roughly Brotherhood and Revelations together, so those memories will probably be the ones with most player time spent in them. Plus he's the only one featured so far in trailers and promotional material, so he's obviously really important in the game.

Benedict Arnold works with the Assassins...
He'll be captured by the Templars on the American side and framed as a traitor in history by them.

Charles Lee is Connor's father
We know Lee had a Mohawk wife. Is it possible that his interracial marriage and children caused him to lose prestige, causing him to hate them? Alternatively, the screens we see of Connor and him fighting is tough love.

The entire American Revolution will be reveled to have been organized by the Templars.
We already known from Assassin's Creed II that George Washington have access to a piece of Eden, and from the information from Subject 16's glyphs that the Templars are very good at manipulating and eventually taking control of governing systems and ideologies that they originally opposed (the Templars originally tried to suppress Christianity and opposed the rise of capitalism, but they eventually embraced these social change and took control of the Catholic church and founded Abstergo Industries). It is totally within character for them to realized that the age of monarchies was coming to an end, so instead of fighting against the tide of social reforms, they allowed the founding of the United States and put their agents into the new government to ensure the Order can survive the new age.

Connor will have some thing to do with wolves.
Altair and Ezio both seemed to have connections with hawks\eagles.Sense wolves are seen in the trailer, maby Connor will have a more wolf like approach to the game.

Connor joins the Assassins in 1772

 * Jossed by new teaser trailer: Connor joins the Assassins in 1770.

William will be killed at an early point in the game
Given that he's the leader of what's left of the Assassins, he can probably shed a lot of light on the order, and if he's related to Connor, he may know enough to spoil the events of Connor's life for the audience. There's also the matter of Daniel and the multiplayer agent being dispatched to kill him at the end of Revelations.

The method of saving the world will have disappeared from the Grand Temple, and Connor has something to do with it.
Revelations ends with Desmond, William, Shaun, and Rebecca outside the Grand Temple of the First Civilization. It stands to reason, then, that the first section of the game will be a platform/parkour sequence as Desmond as they traverse the Temple looking for whatever it is they can use to save the world. When they get there, however, they discover that "it", whatever "it" is, is gone, long gone, and it will be realized (somehow, maybe through Shaun's research of Assassin archives or something) that its disappearance has something to do with Connor, thus providing a reason for Desmond to go back into the Animus and relieve Connor's life; to try and figure out what it is exactly that Connor did and what happened to the thing they need to save the world when the sun goes out of whack again.

There will be treasure/special missions and items hidden on Boston's tidal flats.
Boston, and all through the Gulf of Maine, have very dramatic tides. In Boston, the tides fluctuate by 3 meters (10 feet) every day. That's a whole storey of a building. And if you take a look at a map of the city at the time, you can see that the tidal flats surrounding Boston are pretty freakin' expansive. Perfect place to hide things. Not sure how long each tide would last in the game, but it would present a good timing challenge.

Assassin Tombs will return.
But with the twist that, as part of some sidequest, Connor will visit the remains of characters we interacted with during the AC 2 era, which have ended up in New England. Some possible candidates:
 * Machiavelli. He was an important figure in the order, and his database entry mentions that his final resting place is unknown.
 * Ezio. If only because it would be both touching for Connor to pay his respects to one of the order's greatest Mentors, and a nice Continuity Nod to the Ezio/Altair scene in Revelations.
 * Iskender, the Egyptian Mentor Ezio had his recruits save in Revelations. The incident with the memory seals could possibly be elaborated on.
 * Shao Jun. It would be an good way to deliver some closure on a few things, like whether her mission back to China was successful, or what was in the box Ezio gave her at the end of Embers.
 * Yusuf. It's a bit harder to swing, what with him being  by the end of Revelations, but he could always have been moved out of Constantinople sometime after 1512.

Benjamin Franklin gets his hands on an Apple while in France.
According to 16, Washington's Apple was sent over by the Freemasons from Europe. Benjamin was both an active Mason, and in France for a good portion of the Revolution.

Connor will run into a TWCB that was the basis for a figure in Iroquois mythology.
Or, since the last three games may have played out the surprise god angle, evidence hinting towards it will exist in the Grand Temple.

There'll be at least one Twilight reference
Connor is a Native American with a wolf motif, after all.
 * Oh dear God I hope not.

Connor will be able to sick wolves on people.
Wolves do appear a lot in the trailers, and it is Connor's animal motif after all. They would work the same way as Assassin recruits did in the last two game. You could befriend them in the wild, train them, and with a push of a shoulder button they would come from nowhere and violently maul whoever you're locked on to.
 * That would be absolutely hilarious! (I'm an awful person.)

Connor is Altaïr's descendant
Think about it. WHO did we meet in the previous games that is from ENGLAND, AND, is related to Altaïr? Maybe after the Mongols invaded Masyaf their son, Darim, or one of his children went to England and their descendants went to the Newfound Land (that's the name at that time right?) And one of them fathered Connor.

The Boston Tea Party will be featured...
And Connor is the one who talked the people into doing it. Either intentionally or not.

October 30th 2012 will be an important day
It always bugged me that the release date of AC 3 is 30th October when it was around the 15th November for all previous games. They probably changed the date to let the game appear more current for one of the events.

Connors life will be viewed through an Abstergo Animus.
The colorscheme of the new Animus´ void rooms with light blue/white and some hexagonical strings is very different from the white rooms the Assassins machines utilize. Possibly Desmond will be captured and forced to relive Connors memory for further informations or because they can´t kill him yet.