Kotaku: In one word, "no".
When Final Fantasy XIII was originally revealed, it was slated as a PS3 exclusive. Square Enix was adamant about it. Incredibly adamant.
Then, at the E3 gaming expo in July 2008, the inevitable happened: Final Fantasy XIII was coming to the Xbox 360, but only in Western markets. The game was getting a PS3-only release in Japan. Gamers were sent into a tailspin, with players in Japan wondering if the game was in fact truly a PS3 exclusive.