My guess is that it will remain exclusive in japan (or at least timed exclusive) and it's only because sony have had some sort of deal with SE, M$ already made it clear that they want to take over japan and they probably care about this title's availability on thier platform there.
"Kinect" Games I am really excited about (Click for videos)
Kinectimals Dance Central Kinect-Sports Kinect-Adventures Your Shape Kinect-Forza
Owner of : slim 1000 + 80GB DSlite