POSSIBILITIES (not definites, don't start bashing already)
Best Actor - Ewan McGregor
Best Supporting Actor - Ian McDiarmid
Best Visual Effects
Best Sound
Best Sound Editing
Best Original Score
Best Original Screenplay
Best Editing
Best Director
Best Picture
Now, the chances of the first one and the last three are very slim, but there is still a possibility, seeing as this is the last one, and the academy does like to wait until the last of things to give everything out. Ian McDiarmid does have a pretty good shot, as does all the technical awards. I wouldn't be surprised if ROTS didn't even receive any nominations, but its not a complete 100% no right now.
I think it could win all those mentioned possibly, with the exception of "original score". That's a definate no. Scores of sequels, with relatively the same music, don't really seem to win, and rightly so as it is original score, and as episode 3 will have some new stuff, but a lot of recycled stuff as well...
As for these:
"Best Actor - Ewan McGregor
Best Supporting Actor - Ian McDiarmid
Best Visual Effects
Best Sound
Best Sound Editing
Best Original Score
Best Original Screenplay
Best Editing
Best Director
Best Picture"
Best actor, supporting actor, original score, original screenplay, best editing, best director, and best picture....it'll never even be nominated in these categories, or win. Best Pic, not a chance, same goes for best director and editing. Original screenplay, highly, highly doubtful. Best actor for Ewan a definite no. And POSSIBLY, but doubtful as well, Ian McDiarmid for supporting actor altho that would be cool.