It will sell fine over time, especially if Nintendo force bundles it next year, but will probably be the lowest selling Mario platformer in Japan in quite some time. I think maybe 500k there LTD. Probably North America too, Mario Sunshine did OK over here.
It's not really an indicment of the game though, it's just that the Wii U market is too weak, and with a Mario platformer already bundled with each new system, it hurts 3D World. Gotta find other ways to sell your freaking system, Nintendo, oversaturating Mario has hurt the franchise.