As somebody who lives in the UK, I can safely say that if I did not follow gaming in general I would have no idea the Wii U existed. I don't tend to watch much TV so may have missed Nintendo's ads, but I could bet a lot of money that the majority of people here don't know about the Wii U. My cousin asked not long ago about buying a Wii for her children, with no mention of the attached "U". As for the 3DS, I really do not know. I think handheld gaming may be perceived as an inferior way to game? But as I said I really do not know, I can only say that I often forget Nintendo exists and I do not really get more than fleeting urges to go and buy their products.
Edit: To illustrate my point, if somebody had a gun to my head and said I had to tell them how the Nintendo Wii U worked or my life was forfeit, I would be a dead man. I literally know nothing about the console.
