I think the mistake with NSMB U was that it was released too soon after the 2D Marios on the Wii and in particular the 3DS.
Sales of the Wii U will explode when 3D Mario and Mario Kart 8 are released.
People also have to remember that Nintendo have plenty of IPs that haven't been tapped for years and are perfectly capable of bringing new IPs to the proverbial table.
We're bound to see both Wave Race and F-Zero at some point as well as a Starfox game of some description, and maybe another Kid Icarus game.







