Interesting factoid: The Academy has only been nominating five films for Sound Editing for the last five years (up until 2006 it was only three nominees), and every year those nominees have matched up 4/5 with the Sound Mixing nominees.
Assuming a continuation of that pattern, I might touch up my Sound predictions a bit, but that means that only six films can earn nominations for Sound, and as we know, there are many more contenders than six.
What are the locks? I'd say Inception is safe in both categories, and, despite its absence from the CAS nominees, so is TRON Legacy. What else is there?
Well, if there is a 4/5 matchup, then there can be only one film per category that is not nominated the other. For Sound Mixing, the hopeful that best fills that description might be The Social Network, which has a fine mix recognized by the CAS, but is highly unlikely to grab a Sound Editing nomination.
Now we need two films to join those three in Mixing that can also conceivably show up in Sound Editing. Of the other CAS nominees, Black Swan and True Grit are likely candidates. Shutter Island's nomination with the guild seems like a bit of a fluke.
So Oscar's Sound Mixing lineup might look like: Black Swan, Inception, The Social Network, TRON Legacy, and True Grit.
Now we need something to replace The Social Network for Sound Editing. The options are ample: Toy Story 3, How to Train Your Dragon, Iron Man 2, 127 Hours, Robin Hood, The Town, just to name a few. I feel Robin Hood's a threat. Wylie Stateman has pulled off surprise nominations before. But then there's Pixar's reputation within the Academy's sound branch, and Toy Story 3 (a well liked Best Picture contender) could just as easily squeak in.
It's a conundrum. I may be flip-flopping right up until the eve of nominations, but for now I'll stick with Toy Story 3.