It would seem the first DLC offering for Stacking has been hiding inside the dolls all along. Today, a tipster discovered said DLC's Achievements on Xbox.com and sent us the above screen grab, which indicates it will be called The Lost Hobo King. We have since verified that it's visible on Xbox.com, and on Xbox360Achievements.
The only prominent hobo we can think of in Stacking is Levi, the keeper of records for protagonist Charlie. Hopefully he'll be getting out of that cramped back room and discover his royal lineage!