I don´t think Wii U as it is now poses any concerns for Nintendo.
Miiverse and and TVii are two "weapons" that Nintendo MUST use now to show why it`s not like the console you own right now.
3DS has streetpass, which is a great to interact with other users but that will only work if you carry it with you and if you do find people with one aswell. So, a good deal of it`s value will be lost to either certain countries or groups of players.
Miiverse, on the other hand, can be used by anyone whenever they want too. If Nintendo shows this, it will only work in Nintendo`s favour. And to a certain extant, Nintendo TVii might follow that same path (to anyone).
Wii U, i think is suffering from a few things:
Wii owners had pretty much nothing to play in 2011, besides Zelda and pretty much nothing in 2012. It`s two years of pretty much nothing. And i could bet many Wii owners went for a PS3 or Xbox360 to play games - actually that could explain why MW3 on Wii did so poorly.
Consequences? Despite Wii U having a great line-up, many people who own a Wii U, also own another HD console. Meaning that the market for those core games wasn`t there, although it was for Mario, NintendoLand, ZombiU, Sonic and Sega A-S and Scribblenauts U.
Again, despite Wii U`s line-up being great, it lacked what was needed: a bunch of original games.
That`s why the real test for Wii U will come in the coming months where new games will be released by 3rd parties and Nintendo themselves.
This is where we will see if Wii U is a desired product and how much software the console can sell.
And please, redesign Wii U as soon as possible!
