Nintendo Acknowledges People Think The Wii U Is Part Of The Wii In Commercial

[carlos710]

In Mexico most retailers don't know the difference between a Wii U or a Wii. If you ask for a Wii U, most likely they will offer you a Wii so you better know the difference (and in online shops usually there is no Wii U category to be found, they put all the Wii U's on the Wii category)

So yeah, I would assume there is plenty of people confused around the world.