Yeah, the film is based on a pretty standard well trodden theme. Big greedy white man comes in and takes the land and resources of the peaceloving natives...peace loving natives rally round a hero and win a sucesses against greedy white man. But it is more than that?
The thing about Avatar is that it tells a well-told story well, and it does a great job of re-telling this it, which is why this is a good movie. But in a way, its a bit more than just a re-make of pocahontas.
Essentially, the story format is that of European/American colonisation of distant lands occupied by more primative and vunerable people. Really, on face value this tale would have been more relivent in the 19th century when all this was happening, rather than the 21st century, where the West has nothing left to colonise, all that colonisation stuff is now in the past, isn't it?. But thats the crucial point.
Cameron's movie reminds us that, once upon a time, humanity lived in a culture pretty similar to that of the Nav'i. The Navi are not only like the native Americans, but also like tribal Africans, Celtic Europeans, and whomever came before oriental civilisation. Once upon a time, thounsands and thousands of years ago, we were all like the Nav'i. Then, in the Middle East, the Sumerians and then the Egyptians invented "civilisation". This idea caught on rather fast, then the Greeks took it on, and developed it, and shaped it. This is roughly where we can trace "Western Civilisation" from, this is where it all begins. The Romans are inspired by Greek ideas, and conquor the Celts (the first Nav'i "victims" to western civilisation) Europe becomes "civilised" and in the 1400-1500's they re-discover the American continents,,sent over conquestadors and colonists, and wipe out the Native Americans. The next Nav'i "victims" to western civilisation. In the 19th century things pick up as the European powers colonised India, South East Asia and nearly all of Africa, the next "victims" to western Civilisation. Japan and China are forced into trading with western powers, and through economic and cultural dominance, become noteably more "western". By the time the United States of America becomes the cheif Western super-power, the "west" dominates the entire globe, there are no "nav'i" left to conquor.
Since there is little or no "nav'i civilisation" left, what i think Cameron's movie is saying is that we are in danger of losing touch and forgetting about pre-western civilisation culture, because it no longer exists. Cameron thinks that this could be highly detrimental, and enviromentally destructive, it is implied that Earth's natural enviroment has been destroyed by the humans- a vice of western civilisation is that we do not respect nature. In the movie, Jake Sully is "re-educated" by the Nav'i, as that priestness character repeatadly stresses. Perhaps Cameron is saying that we, the people of western civilsation, need to be re- educated about the ways and ideals and culture of our distant pre-westernised ancestors.
Another point about his film, which is probably more a plot device than anything else, is that the Nav'i strike back against the humans, and win. However, this is consistant with the historical interpretation of the movie. What happens oftentimes is that pre-western cultures strike back, and win a temporary victory over the Western invaders. Boediccia burned down London during her rebellion against the Romans, and Sitting Bull (i think it was him) scored a victory against the Americans at Custers Last Stand. However, these victories where temporary set backs for relentless march of the Western civilisation, Boedicca was eventually defeated*, the Apache Indians were eventually subdued. In the long run, the Westerners win. If Cameron makes a trilogy out of this movie, it would be interesting to see if he consistantly follows this historical pattern.
Essentially Cameron is a Romantic, like Wordsworth, Blake, Roussau and perhaps Coleridge. Civilisation corrupts us, we need to re-discover our natural state, the state of nature. Of course, there is an opposing view put forward by Thomas Hobbes and William Golding in Lord of the Flies that civilisation is a good thing, and are natural natures are evil. Take your side.
Cameron presents this thounsands of year old reacurring conflict in Western history in his movie, not necessarly to remind us of the big nasty white man, but it is more than that. Cameron reminds us of the world we are about to lose here and now on Earth, as Western Civilisation tightens its grip on the human race.
*The irony here is that the Briton's, once themselves the"victims" of Western Civilisation's conquests, go onto pushing the boundries of Western Civilisation like no other nation has done before, conquoring the largest (and last) Empire the world has ever seen.