Awesome.
My only problem with it was with the Colonel, but not because of his characterization so much as how obvious it was that he was going to drag out the fight really long, as soon as his chopper started going down and he was rushing to the power suit... I mean, it was obvious to me then that he would make it to the ground and cause trouble there, because otherwise there would have been no point showing him trying to get into the suit, et cetera. Anyway, I reckon they probably could have had the whole ground fight sequence without it being the 'obvious' ending.
Oh yeah, there is one more thing about it, I guess... at the end, right before the credits start, it says "Avatar" (in text)... that kinda broke the mood, for me. I guess it might help as far as word-of-mouth advertising for the movie or something...
Edit:
And all you people complaining that it's just for graphics whores... Bull****. I saw it in 2D, and it was awesome anyway. And if they had tried to do the same movie without the quality of graphics they used, but instead using puppets or costumes or something, it would have been crap, so I say they were justified in using that much CGI.