America isn't the only market, support by publishers for the Wii U is very poor, and the reception in Europe has been lacklustre. 

Do you actually know for a fact how much money Nintendo has to fall back on if the Wii U fails, considering the 3DS has underperformed and shares have taken a massive hit?

Isn't it a 3rd post on the same topic in last couple of days? Why people are so eager to doom a new console? PS3, Vita and now WiiU. What's their motive?

Nintendo go down this route and they'll be worthless in ten years.

If you give the consumer too much of what they want too fast, you effectively let them dictate your company's rhythm, and consequently they walk all over you once they've had enough.

First: define "fail". Money? Sales numbers? Which one and which amount? 20 million consoles could be a success, even if you don't think that way; just think about the number for a second.. Just because there was PS2 and Wii there doesn't have to be a thing like that every few years.
Second: I should start collecting all these thread titles for future console releases to flood the forums with them when PS4 and Nextbox launch.

I think a good notion for what constitues failure is anything that directly causes stock price to fall or doesn't turn a net profit. I'm pretty sure that's how a company would define a success from a failure.  

PS3 failed after its launch there was many many PS3's siting on store shevels at any given day you could go to any store and see about 15 consoles siting there.

From what I recall, the PS3 had pretty dismal numbers when it first launched too. Since the Wii U is aimed at the core audience a little more, most people want the higher end version, which is what's been hard to find in stores. The cheaper version is available, but no "core gamer" (I hate that phrase) wants the gimped version. We're not really going to have a good idea of how well it's doing until you can walk in to any store and just pick a higher end Wii U up.

As for failure, Nintendo pulled itself from much worse situations. N64 and GC were considerably lower than their competition. With more than a year before any "next-gen" competition really hits the market against the Wii U, they have ample time to make an impression. I myself avoided the Wii for 2 years before gaining any interest in owning one.

So what will Nintendo do? Hold a market with their first party as they always have done. Yet, I don't see a lack of interest for the Wii U, by the reports I've read. Lots of people clammoring to get their hands on one this holiday season.

I think we should throw our Nintendo devices out of the window and go right away to the closest store and buy PS3s and Xboxes by dozens....and some Vitas too

secretly we all hate video games and want to talk about it.

With my definition, Wii U is very likely to fail. I consider selling less than the predecessor to be a failure.