One thing that last year's race for Best Visual Effects made clear was that you just can't beat a Best Picture nominee in this category, even if its effects are far inferior to another contender. But this year, the category's only Best Picture nominee just so happens to legitimately have the best effects of the year, making this one of the night's surest locks.
Even with only this one nomination to its credit, Marvel's The Avengers has reaped more Academy love than all of last year's superhero movies combined. But this is one field in which the genre excels, and the extensive work that ILM put into pulling together Joss Whedon's thrill ride merits recognition. But the Academy's general aversion to all things superheroic will likely bar it from the win.
Visual Effects is one of the categories in which every one of Peter Jackson's Lord of the Rings movies scored, and it seemed only natural that The Hobbit would turn the trick as well. While recent stories that the effects branch put it on the bakeoff list without even seeing it may raise some eyebrows in protest, it almost certainly would have made it anyway. Weta's performance-capture is as effective as ever, but this might be one year the behind-the-scenes wizards of Middle Earth have to settle just for the nomination.
The obvious one to beat is Life of Pi, which has all the makings of a winner: beautiful to look at, convincing CGI “characters” (we can consider the animals characters, right?), loads of created environments, and on top of all that it's a Best Picture nominee. Best Picture nominees never lose this category... unless it's to another Best Picture nominee. I suspect this win to be easy as Pi.
The Alien franchise has historically had a respectable showing in this category, so the inclusion of Prometheus, despite poor critical reception, is hardly a surprise. The stark, foreboding topography of the planet is a wonderfully textured environment, and the film's ominous atmospherics owe a lot to the dense effects work. Still, I'm betting not enough members saw or liked the film to give a fighting chance against Pi.
Finally, Snow White and the Huntsman managed to squeeze in against the more popular Dark Knight Rises, probably thanks to its abundance of well realized CGI. Like Prometheus and The Avengers, this sort of movie just isn't the Academy's cup of tea, however decent the effects may be. Poor reviews don't help its cause, but the nomination (which was never a sure thing) is something of a small victory in and of itself.
Will win: Life of Pi
Runner-up: The Hobbit: An Unexpected Journey
Should win: Life of Pi
Should have been nominated: ParaNorman