I don't see what all the hype was over.
It was okay. I thought the premise was interesting... a nice reversal of the typical aliens-come-to-Earth-impersonating-us-and-harvesting-our-resources movies. But a lot of the acting was weak, and some things were just downright stupid. "Unobtanium"? That's the best they could think up?
All in all, just another CG movie that was about 1.5 hours too long. The hysteria over this movie makes no sense to me.