While not officially saying this is official, Twisted Metal creator of David Jaffe acknowledges that the game's cover art is up on GameStop's web site and, hell, "I figured I'd share a bigger version of it with you guys."
He included another five shots of the box's reverse, so none of this is official, but as none of the variants include a different front, I'd say that, yes, Sweet Tooth is your cover star for the game when it arrives on Valentine's Day in 2012.
That's the fun stuff. Now here's a special message from Jaffe himself regarding commenter reaction to a Hip-Hop Gamer salute to his game, and a couple of other creative decisions that Jaffe's studio, Eat Sleep Play, has made. The first decision was the studio's inclusion of two hip-hop tracks in the soundtrack. The second is the depiction of Mister Grimm as an outwardly black character. White racists have spewed in comments about both choices, and Jaffe's decided he's read and had enough.