@dbot: According to the latest news, the canonical version is the PC one, PS3/360 versions are ports (and likely independent ports as the two architectures are so different).
I agree that there seems to be some strangeness in those claims about portinf from PS3 to 360, especially with these latest news.
EDIT - forget this post, I just noticed I had misread the kotaku report:
http://kotaku.com/5028961/of-course-final-fantasy-xiii-is-pc-bound
My Mario Kart Wii friend code: 2707-1866-0957