Although I know it would disappoint many, you could see Sony looking at the year and figuring let GoW3 and the bigger multi-games get it through to later in the year, then have GT counter the clear focus MS already has on the holiday season, together with bundles and probably Wand as well.
GT will sell however they delay it (as FFXIII showed in Japan) and they can be picking about when to maximize the undoubted boost it will give the PS3, particularly in Japan and Europe.
Try to be reasonable... its easier than you think...