Even if the Wii U is a colossal failure when it's all said and done, Nintendo is still king of handhelds, so they're not doomed. Hell, I think that in an alternate dimension where the Gameboy never existed, they would have already quit the console market.
But I don't think the Wii U will be a complete failure. It's probably gonna outsell the N64. Yes, third-party support is pathetic, and it's probably gonna be like that for the rest of the gen, mostly thanks to a much weaker hardware compared to the competition. But everybody wants to play Nintendo games. I'm gonna buy a Wii U in a few years myself. It's gonna be A LOT of people's "secondary" console.
Of course Nintendo could do what someone already suggested here - make great use of the Gamepad, show people gaming experiences (including third-party) that are not possible at all on PS4/One.
That's what I think honestly.
