If this were any other game, we'd be just about ready to declare this an elaborate joke. But it's Double Fine, so that's, you know, kind of the point.
As pointed out by Joystiq, both Xbox.com and Xbox360Achievements now carry listings for Stacking's first DLC, apparently titled "Lost Hobo King." Other than that, they're pretty vague, but we imagine a full scoop from Double Fine can't be too far off.
Also, those achievement images? Delightful. Never before have we felt so driven to achieve.