I think they wanted money to not go out of buisness.
Hence why the Japan release ISN'T being delayed for the 360 version. They're really short on cash and need money... and can't afford FF13's profits to not be maximized.
They haven't started the 360 version yet... likely because they don't have the resources too, since they are already delaying other games.
So the Japanese version of FF13 will likely pay the bills for the conversion of the 360 game, localization of FF13 in generl and at least part of versus.
Also, i would actually be surprised if Versus stayed exclsuive. I'm betting it's going multiplat and Square is just waiting for the right time to get enthusasm up... since such an announcement would be wasted for them at such a time.