With so many great games coming, and the sales are rising and showing no sign of stopping, i would actually dare say, that Wii U could realistically sell around 45-50M units lifetime, if Nintendo keeps making great games, Mario Kart is the sort of game that keeps a steady line of sales over an enitre generation, and i am sure Smash will do a lot to, so untimely i think Wii U is now fine.