Final Fantasy XIII running on 360 before Japanese release

Last year Square Enix announced Final Fantasy XIII would be released on the Xbox 360 in the west. The company stated that the game would be in development for the Xbox 360 after the Japanese version was finished and released. Apparently they changed their mind, because Motomu Toriyama and Yoshinori Kitase have just shown the game off, running live on an Xbox 360 at the Microsoft E3 press conference. This probably has something to do with the surprisingly early release for the game in Spring 2010.