Are we sure WiiU is getting Mario Kart or 3D Mario next holiday season? 2D Mario already released and its not moving any consoles, 2D Mario is a lot bigger than 3D Mario. They'll have Zelda Windwaker, Game&Wario, W101, Pikmin 3, WiiU Fit this year for sure but...
I don't think these games will move a lot of systems. WiiU Fit will be seen as unnecessary by many casuals as they already have Wii Fit. What will move systems is a big pricecut, coupled with the above games.
WiiU will do well this Holidays but nowhere near the levels of Wii.