The film is *crag*ing amazing, and it is a true milestone in the history of film. It will be remembered for decades.

With that said, yeah, the plot isn't exactly original; if someone were to call it a cross between Dances with Wolves and Ferngully in space, well, they would be right. However, the film makes up for its large amount of borrowed ideas by presenting them in a highly polished, relatively original, and definitely sophisticated way.

The film will be remembered for how much of an achievement in terms of special effects and animation it was for its time. This is probably the first film with extensive motion-capture animation that I've seen to look believable; the characters, scenery, and overall atmosphere create a compelling world and a truly unforgettable experience.

So, while it is somewhat weak in terms of the actual basis for the narrative (The presentation of the narrative certainly isn't, of course), that is a minor qualm when its absolutely wonderous atmosphere is taken in to account.