Changing the interface is only good if it brings in new kinds of customers while keeping your existing market. As we have seen, 3D and Kinect are divisive interface innovations: they lose you your current audience and segment the platform.
Wii U's changes will only be useful if they manage to bring over the Wii new audience AND expand the market more to people who don't currently play games. This can only be done via software, not technology. I see little evidence Nintendo is interested in those who didn't buy a Wii and DS. Indeed they seem to have backed off from the simple, low-budget games that even got them there.
Most of the key titles of Wii and DS (NSMB, Animal Crossing, Brain Training, Mario Kart, Pokemon) hardly used the new interfaces.







