This info comes from somewhere within the depths of Nintendo Power.
Chris H: “If you want to talk about something big, how about the news Hideo Kojima, Snake’s creator, is designing Snake’s level in Brawl? Snake’s inclusion means we’re not only getting one of the best characters in gaming, but one of the best developers as well.”
This has been confirmed by various readers, thanks guys! Thanks to J_Gab for the heads up.