The Wii U by design has aboslutely nothing to do with the Wii. Wii successor? Really? LOL Nintendo just needs to admit they went after the tablet market because of the tablet boom.
It aboslutely has to do with Wii because it is a successor to it like PlayStation 2 was to PlayStation and like it was PlayStation 3 to PlayStation 2...
It can play Wii games, it has backward compatibility and it could play Gamecube games if Nintendo wanted to implement that also it supports all Wii controlers and accessories, also how Nintendo went to tablet market when Wii U is not a tablet because it is a console with a controler that has its own screen that acts as secondary screen like on Nintendo DS/3DS while the game is on TV also that idea was in mind for original Wii yet NIntendo decided to ditch it because it was too expensive for the time.
They did not went after tablet market at all even when that tablet boom was tempting yet they already had DS and 3DS by the time it really exploded in 2011.
You need to admit that you have bias against their console because it is either you don't like Nintendo and/or you don't like Wii U's concept that you think it is a gimmick yet I and everyone else could call PS4 + Vita dual screen and off tv a gimmick because we have a valid reason since it is not in consoles design from the start like the Wii U.
Sony and Microsoft fans called Wii nunchuk a gimmick that was not and yet it also was really close to mouse and keyboard precision compared to regular controllers. Microsoft did kinect that was at least original while Sony made a complete rip off... Sony innovates no more... :/