The only categories that can be harder to understand and judge at the Oscars than Film Editing, are the Sound categories. Not only does the Academy want actors, makeup artists and studio executives deem which among the five nominees has the best sound work, it also expects them to know what the difference between Sound Mixing and Sound Editing is. If you've ever taken part in an Oscar Pool, then you must have spent a long time discussing what the difference between those two categories is, and even if you do know the difference (I think I do), you probably still have problems deciding what actually makes good sound good.
Take, for example, Lincoln's nomination for best Sound Mixing. I'm not saying that the work done in Lincoln is bad, but the Academy has overwhelmed this category with action movies and musicals so much in the past that it becomes dubious whether they're nominating the movie because it has great sound or because they like it (the same goes for The King's Speech nomination a couple years back).
Anyway, what we care about here is what is going to win the Oscar and not necessarily what should, and for that, we need little more than look at some of the previous winners: Chicago, Dreamgirls, Ray. This category has a history of awarding movies that feature a lot of singing and you know there is little movies out there that feature as much singing as Les Misérables. I guess it also helps that the Sound Mixing has kind of become the story about the making of Les Mis, with director Tom Hooper recording the musical numbers live on set. Giving the movies' eight nominations, it seems like the Academy thinks the divisive enterprise was successful.
Still, there's a couple of movies that could take the award instead of Les Mis. I mean, the Academy surely loves Life of Pi. And Skyfall is the kind of action movie that also tends to win in this category. Actually, one of Skyfall's sound mixers, Greg P. Russell, has been nominated for 16 Oscars and is yet to win. Skyfall may just be the kind of beloved movie that can break the curse for Russell.
Will Win: Les Misérables (with Skyfall close behind)
Should Win: Again, I don't know much about sound, but Life of Pi sounded wonderful.