Went out last night and watched Avatar. Some thoughts, but no spoilers...
First, we saw it in 3D, and while it was nice, I'm not sure it needs the 3D treatment. In fact, at a few points I found the glasses somewhat bothersome as they induced a bit of haze. (Yes, they were clean. I checked.) In any case, they didn't play with the 3D all that much in Avatar. They used it, but didn't bang it over your head that much.
What? A special effects movie that doesn't concentrate only on the effects? Well, not that particular special effect anyway.
It was pretty. The cinematography (well... animation, I guess) was quite nice.
The story was, as my wife said, "well worn". I'd call it predictable. In fact, just a few days ago I wrote a review of The Word For World Is Forest by Ursula K. Le Guin, which gives her take on the same kind of situation. My copy of that book has a 1972 copyright, and the first blurb on the first page says "it tells an old story in a new way". I guess Avatar tells essentially the same old story in a somewhat new way.
Overall I enjoyed the film. It isn't something that changed my life, but it was fun.