Embedded in a flash site is apparently the release date for Final Fantasy XIII. That release date is December 17.
Twiddling with the flash's URL brings up this image, which clearly states that the game goes on sale December 17, 2009. Previously, the title was announced for "this winter".
This release date is still unconfirmed. However, Square Enix will be announcing the title's Japanese release date today.
Thanks everyone who sent this in!