Game of the year, so early in the year? Has that ever happened before? I guess it all depends on the lasting impression. Even if its a better game than some of the titles that come out in November, it will be an OLD game. The newer games will be fresh on reviewer's minds and will have somewhat of an advantage.
That's why new games (typically) never make it on "Greatest Game of All Time" lists, even though they get higher reviews than older games. It's all about the lasting impression.