Holy crap, that is the best trailer I've ever seen. If the film lives up to it, I'd say it might draw comparisons to Alien as an atmospheric science fiction film.
I saw this yesterday too, and I must say that i'm thoroughly impressed. Hopefully the movie lives up to the trailer so that Blomkamp and Jackson actually get to make the HALO movie. Although, if this movie rocks enough, who needs a HALO movie?
The GI JOE trailer followed and my boner instantly wilted.