Just saw the film, so a bit late to the conversation but.......
It doesn't do anything to make me feel better about the fact that us European descendants completely decimated native populations and practically enslaved the entire world with our cultures. It's a guilt no movie can or will ever undo, no matter how people may try to make us feel better.
Well, it was bound to happen sooner or later, if not by us then by someone else. Traditional societies, including our own, are generally imperialistic. Human history has been riddled with empires and one group of people conquering another. In some parts of Africa there is still slavery, just like the olden days. Just we developed an advantage and exploited it. Others would have done the same and we would have been under their boots.
Return of the Jedi was originally going to feature Wookiees until Lucas decided that Ewoks were more marketable to the primary target audience (children, whose critical thinking powers are extremely limited). It would have made a lot more sense if the original plan of 7-foot-tall berserk ape-man-things with guns attacking the stormtroopers had been carried out. But Lucas surmised (rightly, unfortunately) that children's movies don't have to make any sense.
Wookies would have been a lot more awesome.
I do generally agree with nightm1r's points, since a Na'Vi "revenge" attack was inevitible, might as well drastically increase the odds of success (the colonel had too much of a "Custer's Last Stand" feel to him). However, taking out that tree was the only way to ensure total victory, since it would have broken the back of the planet's defenses.
As for my own view:
I do have mixed feelings about it. The visuals were stunning, even better than Transformers and the action was well done (Na'Vi got pwned), but frankly it felt too much like a cliche-ic anti-corporate pro-environmental propaganda piece. It reminds me a lot of
Ferngully the Last Rainforest, something I was forced to watch in daycare way back in the day. As for the planet having intelligence (a literal form of the Gaia theory), while not totally impossible, it is unlikely and seemed far too much like an environmentalists wet dream.
