You know, perhaps the purpose of the cubes is not to be a cube....perhaps its just a way to easily add more information to the tiles than they have now, since the tiles are only front/back. Imagine a cube unfolded.
So technically you'll still have a flat face, but now the tiles can flip sideways to reveal different information and up/down for different information. If a live tile is currently a rectangle that is divided into two squares (one is the front, the other is the back) that only flips between front and back, then the cube would be 3x3 tiles in a cross shape that has the main face in the middle, and 4 other faces (up, down, left, right) to flip between. don't really know how that'll work though....could get messy.