Paul Gale has heard from “a trusted source”, that a 3D Mario title is in development for the Wii U. As he admits, that’s sort of a “no duh” piece of information, but apparently the game is set for release in 2013, which makes the nugget a little more interesting. Gale has received bad information in the past, so this definitely has to be considered a rumour, but it also sounds perfectly plausible. We’ll probably hear something at E3 2013.
Source:
http://wiiublog.com/nintendo-is-working-on-3d-mario-title-for-wii-u-set-for-release-in-2013/