Surprise, surprise — I come not to bury Avatar, but to reprise it, to look at it with what I hope to be new eyes. It's been praised and damned in about equal measure, with most of the damnation being one variety or another of the line, "They ripped off [insert name of film/book here]." Under that heading I would place my vote not with Dances with Wolves, but rather Ursula K. LeGuin's "The World for World is Forest". (If she had something to say about Avatar, it hasn't crossed my desk yet — although I imagine if she had, it would have been mighty hard to miss.)
My greatest annoyances with Avatar fall into two categories: plot and sociology. The latter is major and lamentable; I thought the whole Crusading White Guy trope (and the Noble Savage) had been exposed for the fraud it was a long time ago. But perhaps there's a way to address that and the first category in one swoop.
The first third or so of the film would be essentially the same. Humans are on Pandora, mining for unobtanium. The Na'vi live in concert with the planet's ecosystem, which in essence functions as a single contiguous entity. Fine so far.
There's only one problem: Pandora is slowly going mad.
Maybe it's the presence of the human race that has touched this off, or maybe it's just made a bad thing worse. (I vote for the latter.) But for whatever reason, Pandora's world-mind is going senile and its world-body is becoming degenerate. It will take both human and Na'vi to work in concert to figure out what's gone wrong, and maybe reverse it. Both have insights and perspective the other does not, and to put that against the background of Quaritch going scooters would generate a hell of a lot of tension.
This, I think, turns the story from a flat White Man Goes Native story into something a little more intelligent. Both groups have a lot to teach each other, and if we actually show that happening in a way that matters, instead of just wringing our hands about it, it would have become a source of genuine drama instead of a missed opportunity — and a nice way to do an end run around the sociological clichés that riddled the script.
Actually, the conclusion of the story could be further improved by taking cues from another film that preceded Avatar by a good decade, was no less beautiful or fearless with its imagery, touched on many of the same themes, dealt with them more honestly and completely, and gave us an ending that was heartfelt but also quite free of foolish romanticism (although with plenty of romance): Princess Mononoke.