I thought the movie was friggin awesome. I loved it, best movie of the year in my oppinion.
It's so well executed, no detail, even the tiniest ones, are left unattended.
The only negative thing I have to say about it, and really, in my oppinion it's the only thing, is that the storyline is so easy to guess. It's one of the traditional adventure story plots. (For the sake of spoiling I won't go into that any deeper)
But within the first 30min of the movie, I kinda knew how everything would fold out, even though I pretty much already knew it from the teaser.
But I don't really mind that I knew that, because even though I could guess what was about to happen, I was still awestruck by the actors, the scenery, the characters, the effects.. Everything.
Thumbs up, James Cameron! I want another movie from you! And please don't wait 12 years.