What's the point anyway ? The only thing that really matters about Wii U sales is if they sell enough of them to encourage Nintendo to keep making games for it, I think its going to reach that point easily, if it hasn't already.
It's really only the xbox one and the PS4 that have to compete with each other, and even more the PS3/xbox 360, to justify the development of their libraries, long term.
PS4 seems well on it's way, it's the xbox one that's lagging. Not really the Wii U, which has it's own raison d'etre.
Honestly, I'd rather see the Wii U sales stagnate to the point Nintendo has to abandon it. Games aside, it's not a good console, IMO. It needs a proper gaming network, and a means to communicate in-game. The tablet's a good idea as a remote play device, but I think that they should have saved money by putting those capabilities into the 3DS over WiFi, then used the saved money to build a stronger console.
That, and the Wiimotes, I just hate them. Playing
MK8 with tilt controls is inconsistent, as you'll have a character just turn the wrong way at random. The controller's not comfortable to hold if you're an adult (it's too cramped), and then I'm just irritated that
Tropical Freeze is limited to 2-player co-op, because I got my Wii U for 3 people to play together.
Anyway, the Wii U, it's a secondary console to buy, IMO. I got it because it cost me about $150-175 for the console, 2 games, and 2 Wiimotes. Otherwise, I wouldn't have ever gotten it, because $300 just isn't worth what you get, from my perspective. Nintendo has to realize that online gaming is what they need more than anything, and I don't just mean occasional games with no chat feature.
I'd also say that the One is far from in trouble. Like I said, if sales don't pick up substantially as we see the
Madden and
Sunset Overdrive bundles launch, and as the
Halo bundle comes out in November (as well as a new
CoD, which tends to sell better on Xbox than PlayStation), there's reason to worry. Calling the console in trouble because its sales during an extremely-dry summer is pretty pointless.