According to the french news site GameBlog, sources “close to Square Enix” were able to confirm the arrival of Final Fantasy XIII on the PS3 and PS4.
According to their sources, this change in development would have occured two years ago, which could explain why the game has been continually extended for the last few years, and why nothing could be said besides “It’s coming” and “please wait a little longer.”
According to their sources, the game will be a Sony exclusive also. More details will be revealed at E3 2013 this summer (which also coincides with what was said at the Sony conference a few months ago).
Is this a lucky guess? A made up rumor? That remains to be seen. But I guess we’ll find out for sure in a couple of months.