Everything everyone has said about it is true: Dances with Smurfs, Pochahontas in Space, a white liberal guilt fantasy, oh, and, yes, it's stunningly beautiful. The CGI, in particular, I found nearly seamless -- I had the sudden realization, about halfway into the movie, that everything with the Na'vi had to be CGI, and felt both awed and a little dumb. (Anyone else feel like they were watching a video game during the segments where Jake and Neytiri are running along the ground, and the ground turns bright shiny blacklight colors with each step?) The 3D didn't work as well for me, especially not during the action oriented scenes: I felt like it all turned into a big colorful jumble, almost impossible to focus on what was going on. It probably didn't help that my 3D glasses were pretty battered, but I think it's still a limitation of the technology.
The racial politics... well, although not quite as bad as I expected, they were still pretty bad. Other things that bugged me: the complete lack of subtlety to James Cameron's "message". The Na'vi are too perfect to be real, and the humans were mostly cardboard cutouts: the weaselly management type who cares more about his shareholders than protecting life, the jarhead general who is clearly itching to blow up the natives, the grunts who sneer and cheer at the prospect of joining in, the scientist who is blind to the fact that her corporate masters only tolerate her experiments as long as they further the goal of getting more unobtanium (what was I saying about subtlety?). When the lead Marine referred to going after the Na'vi who were massing for an attack in retaliation for the destruction of their home tree as "fighting terror with terror", I literally rolled my eyes. Way to mash up your diatribe against the Iraq war with stern messages about colonialism and environmentalism, there. It's kind of a mess, politically, and maybe it's a mess with its heart in the right place, but when you step directly on the what these people need is a white dude trope in the process, I have a harder time giving you too much credit.
From another review that takes on the racism angle:
By the end of the film you’re left wondering why the film needed the Jake Sully character at all. The film could have done just as well by focusing on an actual Na’vi native who comes into contact with crazy humans who have no respect for the environment. I can just see the explanation: “Well, we need someone (an avatar) for the audience to connect with. A normal guy [read, a white male] will work better than these tall blue people.” However, this is the type of thinking that molds all leads as white male characters (blank slates for the audience to project themselves upon) unless your name is Will Smith.
I would totally have watched a movie where Zoe Saldana filled the Jake Sully role. In fact, I might well have been first in line. Hell, give me the adventures of Zoe Saldana, Sigourney Weaver (the naive but also pretty damn awesome scientist), and Michelle Rodriguez (a Marine pilot who switches sides), and I'll go see it every week. Can that be Avatar 2? (Oh wait, no, it can't. Because two out of those three characters are dead. Which gets into the sexual politics of the film, which are not quite as bad as the race issues but still worthy of discussion, but that's another post.) It's long past time to expand our storytelling modes to focus on different kinds of stories and characters, and I eagerly await the day that awesome special effects are utilized in their service.