I included "so far" in the thread title for a reason. The Prestige seems like a good candidate right now, but I doubt it'll survive as the bigger films are released. Michael Cain is the only one who may get nominated. Any other nomination may be stuff like best costume.
The Departed and Flags of our Fathers are the two that will stick with people till January when the nominations are announced.
I can see Departed getting nominated for:
Best Picture
Best Director-Martin Scorsese
Best Actor-Leonardo DiCaprio
Best Supporting Actor-Jack Nicholson
Best Screenplay
Best Editing
and possibly some more.
As for Matt Damon. . .if he's nominated for anything this year it'll be for The Good Shepard.
And, Flags of Our Fathers will get the usual nominations that come with these war films everyone loves.
So, anyway, like I said before The Prestige may or may not survive with the upcoming films. We need to be on the look-out for films like The Fountain (which looks awesome and may get Hugh Jackman nominated), that new Mel Gibson film (which may or may not get affected by his backlash), The Good Shepard, The Good German, and some others I can't think of right now.
As for Christian Bale, he has two other big profile films being released this year. So, lets see what happens with that.
EDIT: Now, that I think about, Christian Bale won't recieve a nomination for The Prestige. Rescue Dawn, directed by Werner Herzog, is the film that Bale may be nominated for. IF he gets nominated for anything it'll probably be for that since its about Vietnam and what-not.
So, yeah, Michael Cain is the only one likely to be nominated. If Bale and Jackman are nominated for anything it'll most likely be for The Fountain and Rescue Dawn.