I don't think it will sell like wii because i think wii u is less innovative then wii and it has many port of ps3/xbox360 game
PS4 - over 100 millions let's say 120m
Xbox One - 70m
Wii U - 25m
Vita - 15m if it will not get Final Fantasy Kingdoms Heart and Monster Hunter 20m otherwise
3DS - 80m







