From what we know so far :
FFXIII
all team are working on PS3 version (japan),
when the game will be ready, it will be released on japan
THEN they will adpat the PS3 version to PAL/NA territory + make the xbox360 version
when it is ready, it willbe released in PAL/NA
VERSUS XIII
we know nothing, it is a PS3 only game
Last note :
- possible FXIII xbox360 port in japan not excluded
- possible Versus XIII xbox360 not excluded
Time to Work !