Wouldn't it make more sense - looking at the sales - to make a home-version of the 3DS? Well, that would rock. Hmm, I could think an upgrade of the WiiU, making a 3DS cartridge-slot into the gamepad and playing 3DS-games on your WiiU. Two screens are there. The lower is a touchscreen. It could work, we would only lose the 3D (except for 3D-televisions).
EDIT: important addition: This idea struck me while reading a thread on VGC.