I don't really want to compare Avatar to anything, because that would bring down the other movies. Glitz and glamor is really all this movie offered. I didn't get an emotional movement, other then the eventual "wow" at some of the battle scenes, which were well done. That's about it though, lot of flash, lot of eye popping special effects but aside from that? Nothing more.
It's a good movie for what it is, an action/sci-fi/love flick wrapped in special effects. To call it "ground breaking" or the "future" of film making? God, I hope not. I don't want my movies to replace storyline and substance with pretty lights and things that go boom.
Aside from the other negatives other have given. I'll point out some positives. A good re-imagining of Pocahontas. John Smith as a crippled Marine and Pocahontas who painted her body with "the colors of the wind". While aimed more at an older audience, a lot of this felt Disney like to me. It was a "break out in song and dance" away from being just that.
You might look at that comment as another negative, but seriously. Where in this film to you find an "original" theme? James Cameron for all he's done in the movie industry isn't doing anything ground breaking. He's good at taking stories and giving them a different perspective. He took the story of the Titanic and made it a love story, he took the Story of Pocahontas and made it up-to-date/futuristic.
Again, it's a good film to sit down and see, just for the fact that it's good enough to sit through in its entirety, at least for me it was. However, it's not doing anything praise worthy for the movie industry or for my faith in Hollywood. It's a summer block buster that got released in Winter. Had this been a summer block buster, it would be in the same crap pile as Transformers 2.