There are several reports on this out there by now, but I'll link to this one from Joystiq.
What's happening is Sony France's boss mentioned that the exclusivity of FF13 is 'in discussion'. The article brings up a good point: was FF ever exclusive anyway? Most of us know FF7 and FF8 were on the PC not too long after the PS1 version came out. It could be that the later games were 'only on playstation' because it was most profitable for them to keep it there and not bother with porting it over. If they saw an opportunity to make some more money with a port, I'm sure they would have done it (FF11).
That could be the situation FF13 is in. No one is really sure if having their game 'only on PS3' (or any system for that matter) is really profitable. The PS2 had a commanding lead in the outgoing generation, so FF could sit pretty on PS2 and not have to worry about making money. PS3 doesn't have that guarantee of profit at this point, and it still may not by time FF13 comes out.
If Sony wants to keep FF13 as an exclusive this time, they may have to pay up. No longer do they have the luxury of saying "Your Game + Playstation = $$$." Judging from recent announcements--beyond Devil May Cry and Ace Combat--Sony hasn't fought hard enough (if at all) to keep some of its prior exclusives. Final Fantasy is one of their only remaining established heavy-hitters. From what I understand, Sony owns some small stock in Square-Enix, so I'd imagine they'd hold on extra tight to this one.