I don't know which will sell more, but I feel that even when each one will have motion control, sales will be quite independent from each other, each console has a "personality" defined enough, by now, that it sells based on its own features and SW offer (and saturation of its own potential market), without "stealing" users or being "robbed".
Even Wii shouldn't be "robbed", if Move and Natall succeed they'll have found a new market that didn't want a Wii anyway, otherwise those people should have already got one spending less than to buy a PS3 Move or a XB360 Natal.







