It'll continue to sell millions of copies on current gen systems no question.
Ask Nintendo how Black Ops II sales on Wii U have gone for them.
yeah but... Xbox720/PS4 represents a big jump
Wii-U is still technically current gen.
The main problem with WiiU is that it offers NOTHING except a tablet over the 360/PS3. OS/Services, the WiiU isn't even in the same ballpark.
We will see a huge uptake in sales when the next consoles come out... probably a lot larger than most expect.