Recently, due to Xbox Japan boss Takashi Sensui not denying rumours that the Xbox 360 will be exclusive, rumours sprang up that the title, being made for both PS3 and Xbox 360 might have been taken by Microsoft to be exclusive to the latter console.

Earlier today, Capcom announced that there was no plans for any forms of exclusivity to happen at this time.

"Resident Evil 5 will release on PS3 and Xbox 360 as announced. There a no plans for an exclusive with the game"

[Source]