I remember when the Wii was announced in 2006 (after some previews as the Revolution), people were hyped for it. It won NUMEROUS awards, and people wanted it very badly. The media reacted as well, including an awesome South Park episode - people wanted the Wii.
Wii Sports was a brilliant pack-in game that turned the Wii into a phenomenon. Then it launched with Zelda for the hardcore gamers. Nintendo kept up the momentum until about 2010 and then it just went flat. The Wii lost its hype (but still sold pretty well).
And I think that will hurt the Wii U- the non-gamer casuals that bought the Wii won't know what to think of it. "Oh honey I hear a Wii U is coming out." "Oh, does that go with the Wii, that thing we threw in the attic a few years ago?"
And hardcore gamers aren't going to get it like the Wii because the graphics aren't up to par (really Nintendo? Come on!) and let's face it, Nintendo games just aren't generating the excitement they used to.
The Wii might have been a gimmick but it worked - it gave a new way for gamers to play and they ate it up. Nintendo thinks that because tablets are the in thing now that people want this controller but they don't. It will offer nothing new for games (maybe a map like 90% of DS games) and is expensive and lame.
Overall the Wii was a brilliant idea, but the Wii U is just meh and will NOT re-create the success the Wii had. It may sell 40 million units, good for a Nintendo console.
I believe it will truly be the worst Nintendo console ever, beating the Wii and N64!