Tell me how the Wii U is doing. Is it building on the "success" of the Wii? Was the Wii's success sustainable?

The answer to these questions is no. The Wii got a lot of people who would probably never buy a video game console to buy one. But where are they now? How many are shoved under a TV in the spare bedroom at someone's grandparents' house? Why haven't they bought a Wii U yet?

It's because it was a blip. It wasn't sustainable.