Square Enix have released the first tit bits on Final Fantasy XIII-2, which takes place a few years after the events of Final Fantasy XIII. Here's the story blurb:
"Set a few years after Lightning and the others saved Cocoon, some survivors have decided to start over by rebuilding on Gran Pulse. Lightning, however, is nowhere to be found and thought dead by many, but Serah believes otherwise. When her town is suddenly overrun by monsters, a mysterious man named Noel appears to save her. Together, the two set off to find Lightning," Square Enix revealed.
The first two screenshots had leaked a bit too early apparently and Square Enix have requested they be taken down. You'll have to wait until June 6, before you see them again.
Not much can be said other than it looks like FFXIII. The game set for release before year-end for both PS3 and Xbox 360.