hmmm I really dont know right now but MGS4 really tempts me to get PS3, and the Wiimote to get the Wii, so I put both.
I'll probably get the Wii, if it does alright.
The only complaint I've heard about it is that you have to play along with it, meaning that if the game asks you to put the Wii at your hips and do a hula-hula, you might easily cheat by wagging your wrists....
I think this could potentially ruin it, if it ends up coming down to wrist movements.