Update: After doing a little digging, we've uncovered the source of this story. Tanaka's comments come from an interview with Pro-G, so it looks like the upcoming 360 MMORPG from Square-Enix is the real deal, folks.
Say it with us now: "whaaaaa?" Coming from our friends at Xboxygen (they're like, totally French), is a dandy of a rumor: Square-Enix is currently developing an MMORPG for the Xbox 360 and Windows Vista. Perhaps the most interesting part of the rumor, the game may not make it to the PS3 at all. Hiromichi Tanaka, director and executive producer of Final Fantasy III for the DS, reportedly made this announcement in a recent interview: "We're working on a next generation MMORPG for the Xbox 360 and Vista but a version for the PS3 is possible."
Assuming this is true, we can only guess as to what the MMO will be. Considering that Final Fantasy XI is already available for the 360, it's not too much of a stretch to assume it might get a sequel. Still, the important thing is that Microsoft may be getting more Square-Enix love in the near future. Could a legitimate Final Fantasy be in the works as well? We can dream, can't we?