The sellthrough rate. I am not sure about the exact ranges, but it's something like this:

Running: >75%
Jogging: 50-75%
Walking: <50%

Remember the Wii? One of the key points was that conventional controllers posed a psychological barrier due to their amount of sticks and buttons. Nintendo succeeded, because they removed this barrier to entry with the Wiimote. People bought Wiis in droves, because the controller was different and the games were different. However, with the Wii U Nintendo went back to the pre-Wii days with their controller design. Just because they put a touchscreen on it doesn't make the conventional controller awesome. People got accustomed to the Wiimote and then Nintendo puts out this monster of a controller that goes completely against what the Wii stood for. Sure, Wiimotes still work on the Wii U, but they are not the main controller anymore.

Yes, I can see how the Wii U controller can be a barrier for casual gamers, but that shouldn't stop it selling to more core centric players - the crowed that bought PS360. But of course, I can see a whole lot of arguments why they wouldn't by it... But, if (and that's a pretty big if) Wii U gets all the 3rd party games as the future PS720 would you still deem it somewhat of a failure?

Regarding novelties, the DS already used a touchscreen, so the Wii U controller wouldn't have been anything new anyway.

Yes, but I doubt a lot of adults played the DS... Some how I doubt the soccer moms that used the Wii Fit picked up the DS as well, so for them it would still have been a novel idea (that is, before the launch of iPad)

For Japan specifically, we have seen the market moving towards handhelds, because mobility is much more valued than graphical prowess. The Japanese play their handhelds everywhere, including at home. Nintendo's thought process must have been that their home console can benefit from featuring off-TV screen play, because it's doing the same job as a handheld within people's own four walls. But all this will do is cannibalize the sales of either their handheld or their home console. The system that gets the games will be fine. The system that does not, however...

This is weird, because I can swear I just read in another thread that you don't believe in cannibalization... But I get what you're saying with regards of how the Japanese prefer HH.

Sony faced this exact problem in the seventh generation. The PSP cannibalized PS3 sales*, because a handheld is the superior choice in Japan (unlike in the rest of the world). There are two ways to keep home consoles alive:

1. The home console gets a good number of big exclusive games. That was basically the saving grace for the PS3, because many big main series games weren't released on the PSP. Also, since the 360 was practically dead in Japan, every multiplatform game was effectively a PS3 exclusive.

2. The home console offers games that cannot be replicated on a handheld (this can be combined with point 1). This is why the Wii wasn't cannibalized by the DS**. You simply can't make Wii Sports or Wii Fit for a handheld.

For the Wii U you better don't get your hopes up that point 1 becomes reality. For point 2 it isn't properly equipped, unless Nintendo goes back to their Wii ways and emphasizes the Wiimote again, because the Gamepad is very similar to what you get with a 3DS.

*The PS3 and PSP received the vast majority of third party support (like usual for Sony) in the seventh generation. Sony had two systems on the market, but their sales didn't double over the sixth generation. PS2 did about 22m, the PS3 and PSP combined will maybe end up around 33m.

**The Wii received hardly any third party support. The DS only during the middle of its lifespan; the beginning and end were rather dry. Essentially, Nintendo had similar support as in the sixth generation. The Wii outsold the GC by a factor of 3, the DS outsold the GBA by a factor of 2. Huge gains in both cases, because Nintendo managed to attract new audiences while giving both of their systems unique identities.

The ps3 version of LBP karting released, but the Vita version doesn't release until 1/31 I believe. I wouldn't expect great numbers for it though.

If the Wii U got all the third party games, then there wouldn't be much of a problem, because the Wii U would be the cheapest option to get all those third party games. That alone would lead to respectable lifetime sales, although they would maybe still fall short of the Wii total, depending on Nintendo's first party output. It certainly would be out of failure territory in that case.

America buys an enormous amount of handhelds for kids, soccer moms do have kids by definition, the DS had games like Brain Training, Tetris, NSMB and Mario Kart. It's hard to imagine that the idea of a touchscreen gaming device would be a foreign/new concept to a lot of people, simply because there were so many DSes sold and because it's clear that this handheld managed to sell to adults too.

Yes, I said I don't believe that two different games from the same series are cannibalizing each other when they are put on two different systems. If you read my post in this thread regarding consoles cannibalizing each other, you'll see that I point out that exclusive games diminish the effect of such a cannibalisation. When you apply this concept to the Western markets where home consoles are seen as superior to handhelds, then handheld consoles should suffer when they aren't able to distinguish themselves from home consoles through either exclusive games or unique features. If you look at the PSP again, while it did cut into PS3 sales in Japan, the opposite effect occured in the West, especially in America. Particularly software sales nose-dived once the 360 and PS3 gained traction. Since the Vita employs the same strategy as the PSP, it will fall into oblivion once the PS4 and Nextbox are launched. The Vita had basically only two years to prove itself in the West; Sony already wasted a year and this year doesn't look any better for them. They'll run out of time, so if the Vita manages to find success, it will only be in Japan.

As for Nintendo turning this around, it's going to be difficult with the low third party confidence we are seeing. Maybe the upcoming Nintendo Direct for Wii U third party content will be positive, but I wouldn't get my hopes up. Nintendo will have to prove the worth of their controller and they pretty much have to do it with something that doesn't fall into the category of a minigame. I am not thinking of singleplayer games here either. It's got to be a multiplayer title to really catch attention, highlighting assymmetric gameplay in a big way.