You may remember Gearbox showcased a trailer for Aliens Colonial Marines in September 2008. It was a private function and cam footage of it was leaked back then. The actual teaser trailer has now been leaked in high quality. It starts with a shot of a planet and then pans to Alien eggs with marines exploring in the background. A facehugger jumps out and the clip ends.
The trailer was produced by a company called Digic Pictures who seem to have done several game trailers. Thanks to 4H0-DMT, Ikarop and Xhan for the news.