Well, GoTY nominations tend to be bought not earned so it's hard to say.
2011 was supposed to be a huge year for Blockbuster games, and EA in paticular has been flooding the market. It hasn't turned out that way though, and truthfully a lot of these blockbusters seem to be fizzling down to pretty run of the mill successes, if that (sales aside). "Dragon Age 2" was badly received, and despite the fanboyism I honestly do not think that "Portal 2" has had rating difficulties simply due to Day1 DLC, largely because even when it's inspire anger it hasn't lead to that kind of reaction.
Upcoming titles like "Mass Effect 3" and "Skyrim" are very much in a "wait and see" catagory because despite the success of "Mass Effect 2" it divided the player base, and even Bioware has kind of acknowleged they went too far in the shooter direction, and are trying to modify things to appeal more to the RPG crowd, with a new engine comes entirely new questions on how well it will succeed. "Skyrim" looks awesome, but then again despite the protests of the fan base for "Elder Scrolls" Bethesda has continued to trend of dumbing things down and simplifying them. Skyrim is the prettiest "Elder Scrolls" title yet, but it's also the most simplistic, and for a series that is successful largely because of it's scope and depth, I could see this backfiring with a lot of the fans (after they buy the title) since Bethesda seems to simply not be listening to their feedback from previous titles in this regard.
If I had to pick I'd say that it will probably go to "Old Republic Online" assuming they manage to get the game out this year. Nothing reliable, but there has been some word of mouth that the game is pretty much done, and the delays on a release date being annouced are business related. Simply put they want to do all these pre-order deals and such, and there are fights between various retailers and the company because so many pre-sells are expected that nobody wants to be one-upped for this release in paticular. Gamestop in paticular is REALLY big into coming up with more money than anyone else to ensure they get the best pre-order incentive content compared to their rivals, but at the moment it's compettitive because nobody wants Gamestop to have that kind of advantage and they are willing to put up the money. Of course this is a rumor FROM Gamestop employees claiming knowlege of inner industry workings so well.. take that for what it's worth. It sounds like it could be true though, so we might still be seeing "Old Republic" by year's end.
A dark horse nominee from me is Funcom's new MMO "The Secret World". Before anyone laughts I *WILL* say that despite their failures, Funcom has innovated a lot of things within the genere, especially with "Anarchy Online". Things like the "Apperance tab" a seperate set of equipment that is visible as opposed to only what your wearing being visible, are pretty much their idea, and are being imitated (by all reports) by things like "Old Republic Online". It seems like they are actually looking to do some pretty radical things with "The Secret World" and while the odds are on another spectacular failure, chances are it will have some ideas that will be imitated heavily in the next generation of MMOs, and if they finally manage to actually pull off a successful MMO despite all the odds, I could see this one becoming a critical darling. Sort of like how games like "Demon's Souls" and "Cryostasis" snuck in to pull high ratings in previous years.
Battlefield 3 is a decent choice as well, but largely because of the FPS wars going on right now. I could see enough money being paid to review sites to get the nomination, simply for the hype to make it more competitive with "Call Of Duty".