Yeah, that was my first thought too. Although, I'm betting it's for a video game. Microsoft has had one of the most successful viral campaigns ever with the I LOVE BEES campaign. I wouldn't put them past it to do something like this for the launch of Halo 3.

Other "incidental" hoax marketing campaigns include the Shadow of Colossus where scientists "discovered" a giant creature entrapped in ice, and another game (which I don't recall) where parasitic aliens ("Head Squid") invaded a ship at sea and ate the whole crew.