They could surprise us, but generally (and I think this has been gone over in another thread) there's a certain kind of politics that goes into the Oscars. If a movie is a lock for a certain category it will often be overlooked in other categories. It's a glorified trade show, more or less. Now that the Weinstein's don't have a lot of Oscar muscle anymore it tends to come down to what got all the critical praise, what was most popular, and what the Academy feels is most "relevant" (see: Crash) A Serious Man was pretty divisive. It got critical approval but not enthusiastic praise. It's a difficult movie to explain (damn near impossible to explain in a sentence, unlike, say, Avatar), it's straight-up deadpan comedy about a middle-aged Jewish guy in middle America, with no Names outside the director's chair. Whether or not it's any good is sort of beside the fact that no one has seen it and it is far and away the least sexy nominee.
Anyway, the dramatic narrative since the Golden Globes has been James Cameron vs. Kathryn Bigelow. Avatar stands to win because it was huge, but one should also consider that the whole reason they expanded the Best Picture list to 10 was because they felt their lack of consideration to big-tent pictures was turning people off. They might give it to Avatar because they didn't even put The Dark Knight in the running last year. Up in the Air could certainly make it, it was the odds-on favorite before the Golden Globes and it's an agreeable (if not all that great) movie.
Up is in the animation ghetto, I wouldn't expect it to win. Precious has a best supporting actress statue locked in, the director is being a dickhead in public (and he's not James Cameron), and like A Serious Man it is not sexy at all. An Education was very well-reviewed but nobody saw it, so it's The Reader of 2010. No love for genre pictures = no love for District 9, plus no stars in that film. Who knows what the fuck The Blind Side is doing there. Inglorious Basterds will probably net a Screenplay statue, plus that movie fucking sucked.