Nintendo often gambles on hardware. Whether you call it gimmicks or innovation, they've shown that they want to differentiate themselves from their competitors when it comes to how you interface with games. Some people like this and think it keeps gaming fresh and moving forward, some dislike this because they feel it takes the focus away from the software.
The upside is that, now and then, they might capture the collective attention of gamers and non-gamers alike and have their product go viral. The downside is that they might end up impressing neither.
I suspect that, this time, the gamepad is closer to representing the downside than the upside. Nintendo made it the focus and, unlike the Wiimote, the hardware really isn't selling itself. Only hardcore Nintendo fans are genuinely excited about the Wii U as a system. If that continues to be the case, then Nintendo's games are going to have to sell the hardware. That wouldn't ordinarily be a bad thing, though it would likely mean a lot less casual attention, except that the focus of the Wii U being on the gamepad means the rest of the hardware isn't as robust as it could have been.
Now, that said, I'm not saying this is a DOOM situation. I think the Wii U will be just fine if it has to depend on Nintendo software. It just won't get near the Wii in terms of sales. And, of course, the gamepad might catch on if the right software comes along that really pushes the hardware into the collective unconscious of the general public. I don't know if that's likely, but it's always possible.
I wouldn't say Nintendo rolled snake-eyes with the Wii U, but I also don't think the gamble will pay off nearly as well as with the Wii. That's Nintendo, though; good or bad, they roll the dice.
