I don't think this is about the 'U' in 'Wii U'. Frankly, I prefer it ten times over Wii '2'. Haha
In fact, I think people have trouble with 'Wii'. It became a brand in itself with its new market. And it got stuck with it's 'casual' reputation. I think people just want the 'Nintendo' name to be part of it again.
I think people would actually like 'The Nintendo U' or 'The NU' ("New") :)
It's still the 'you' paradigm they want, but they can always put on the box and promo stuff "Works with your Wii controllers!!" (: