Just got back from seeing it. Firstly the picture was amazing, the 3d was just stunning at times, everything about it was beautiful.
The film itself was amazing. I haven't been that impressed with a movie for a very long time... in fact, I can't remember the last time, probably since I was a kid.
I'm not going to say it was the best movie ever, it wasn't, it had its flaws. My biggest gripe was the sheer length. For a very brief moment during the middle of the movie, (before the big things start to happen) I realized my back was aching a little bit, I found myself wondering what time it was and how long was left, but that was only briefly. There are other small faults that I cant really describe without spoiling the movie.
I was surprised to find myself completely forgetting that I was watching a computer animated world for much of the movie. This is something that's NEVER happened to me in all modern movies I've watched, I've always known I was watching a computer and it was one of the biggest doubts I had before going in to see it. This movie alone demonstrates just how well computers can be integrated into movies and sets a standard that others should try to follow. Its not about how many pixels you can fit and shade together, its about how its delivered, and this is why James Cameron is one of my favorite directors.
Overall I'd give it a 9.5/10. It was predictable at times and the "theme" of the movie has been done before. It had some cheesy moments and occasional awkward script (especially the beginning,) however! It was almost perfectly put together and was an epic adventure that really makes you realize just what a movie can do. It wraps its hands around your emotions and brings you along for an amazing journey that at times makes you want to escape to its world. Its restored my faith in movies.
"The chiefs daughter was fit" I overheard on my way out
Highly recommended if you can see it in 3d

I can most definitely see myself buying it when released on Bluray.