"They would have to seriously decrease the graphics (remake textures and models), they would have to port the game to the Wii (requiring extensive testing and programming), and levels would have to be redesigned because the Wii simply can't have as much on screen as the PS3 and 360 (requiring a rework in the game and level design). "
Here is the thing though. Didn't Capcom do just that for RE4 when it went from GC to PS2? Sure going 360/PS3 -> Wii would probably be harder than going GC -> PS2 but given the work they did there i have every confidence that Capcom can do it.
"I do not suffer from insanity, I enjoy every minute of it"