The thing about visual effects is that the more they are utilized in movies, the less impressive they seem. We have come to a point were our multiplexes are saturated with computer generated imagery, or "CGI". Almost every movie uses computers in one way or another to tweak its visual style. And more often than not, CGI is used gratuitously whenever a script demands for something unrealistic or fantastic to happen on screen. Long gone are the days of miniatures and matte-paintings and the Academy Awards, by refusing to nominate movies that largely used practical effects (Skyfall) or that only used computers as a supporting tool (The Impossible, Looper), reflect a world of CGI dominance. It's actually come to a point where not only things that could be achieved through practical effects are done with computers, but where things that would be better off achieved through practical effects are done with computers.
Case in point, Peter Jackson's The Hobbit: An Unexpected Journey turned its Orcs, which were effectively scary men in costumes in The Lord of the Rings, into the least-believable computer animated villains since the vampire-zombie hybrids of I Am Legend. Jackson is a man who normally knows how to benefit from using computers, but this time I'm hoping that the fact that we get to see Gollum once again doesn't translate into an Oscar for The Hobbit's effects.
Yes, the Hobbit is, in my opinion, the least deserving of the nominees. Even if they're movies I don't like, nominees like Prometheus and Snow White and the Huntsman undoubtedly use their visual effects as a tool to make their movies more effective, as they help establish a tone (instead of destroying it, like Jackson's orcs). My love for The Avengers is well established and I guess part of the credit for making The Hulk into the most memorable character of the movie rightfully should go to the movies' visual effects artists.
However there is little doubt that the ultimate visual effects achievement of the year is Ang Lee's Life of Pi. A movie, again, that I had problems with. But one can't deny the outstanding work that was put into creating the CGI-tiger that goes by the name of Richard Parker. Like I said before, we're at a point where computer generated images don't impress moviegoers, so the fact that Richard Parker is such an impressive creation will surely guarantee the Oscar.
Will Win: Life of Pi
Should Win: Life of Pi