Comparing Wii to WiiU sales of the major nintendo titles already out we can see that the Wii games are selling at well over twice the rate of the Wii U games. The only exception is Smash because the Wii version only launched in Japan initially. As we can see by the massive jump on the Wii version's graph, once it launches in Europe and America, Smash will also be selling at well over double the rate on the Wii as well.
Mario Kart
Smash
Donkey Kong
New Super Mario Bros
3D Mario
Assuming Zelda managed to hold on a little better and only drops to half the sales of twilight princess that means it will sell 3.5million. Assuming it sells half of total wii/gamecube twilight princess sales it will sell 4.3million. Assuming its drop is just straight up the same as the other major Wii U titles it could sell less than 3million.
