District 9, a movie produced by Peter Jackson and directed by Neil Blomkamp, is not a decoy title for Halo. It is about a race of aliens who is forced to live amongst humans. That doesn’t nearly go along the lines of Halo. Don’t let the rampant rumors fool you. The trailer can be seen here.
The movie will be shot in documentary style, much like Cloverfield and the Blair Witch Project.