My solution would have been to come up with fresh and exciting new name that differentiates the system from the Wii (in order to further solidify the idea that the Wii U is for core gamers). Nintendo Revolution for example.
In order to make sure the casuals are not confused I would put a sticker on the box for the first year or so of its console life that says something to the effect "Play your Nintendo Wii games and use your Wii remotes/accessories on Nintendo Revolution!"
This seems like the best of both worlds to me. You get a new name so Nintendo gets some level of credibility in their attempt to grab the core gamers, and casuals should, for the most part at least, realize that the system is a successor to the Wii, and they can use their old Wii stuff on it (Nintendo's been really awesome when it comes to backwards compatitibility in the last decade so it would advertise this selling point as well).
