While, Ilomilo has not yet been given a release date on Xbox Live Arcade you can actually pick up it as soon as today. If you follow this link to a "super secret" code giveaway for the demo version, you can just upgrade to the full game by paying 800 points. It will probably get officially released on XBLA very soon, but if you want to get it early you should go ahead and download the demo with the code.
Ilomilo is a cute platform-puzzler developed by Southend Interactive (Deathrow, R-Type Dimensions, Tecmo Bowl Throwback).