Nintendo World Report
, a website that reports all things and only things Nintendo, have released an image that they claim to be a leaked picture of a new suit in the upcoming 3DS title, Super Mario 3D Land. The picture contains Mario in what's been dubbed the "Boomerang Suit", which is clearly derived from the infamous Nintendo enemy, the Hammer Bros, who were introduced back on the NES in Super Mario Bros 3. NWR says that this is an image that was not intended to be shown, thus truly making it a "leaked image". Nintendo has yet to comment on whether this is a confirmed suit in the game or if it's just a hoax. Judging by the high quality image that was released and the credibility of the leakers, I think it's safe to call this one...CONFIRMED.
(that was a little Mythbusters reference there... :D)