@mamp, there's only 20 million of us? Well I guess that explains the Gamecube's sales then ._.
Anyways, I think the Wii U will have okay success. It won't be a failure by any means, but I just don't see it doing anywhere near as excellent as the Wii did. It just doesn't have that "wow" factor for the average consumer. For many Nintendo fans, this will be a great system, but the success of the Wii is very hard to follow.
I hope I'm proven wrong of course.