The DS would make a great Wii controller. That means more of the interdevice connectivity that is so widely touted for the PSP in its relation to the PS3. The DS would add a new dimension of control to the Wii because it would allow users to be able to utilize the touch pad in addition to the Wii mode. Maybe you can have some kind of shooting game? Nintendo DS Blog is a great authority on the DS and they currently say that nintendo has no plans to bring cross platform connectivity to the Wii or the Nintendo DS.