To answer the topic, people really need to realize that an open world 3D Mario, a new entry in the The Legend of Zelda franchise, Mario Kart 8, Super Smash Bros. 4, Metroid, Mario Party, Animal Crossing and tons of other smaller and greater system selling franchises have not been released for the system yet. Wii U lifetime predictions at this point are useless, and will still be even after Mario Kart 8 is released.
With that said, Mario Kart is a franchise that has seen massive growth in recent years. I would be stunned if it does not sell over 10 million copies by the end of its production. Especially considering the possibility of backwards compatibility and 7th gen Mario Kart titles still selling to this day - six and nine years following their release.







