I'm an American, so this doesn't affect me outside of the fact that the liberals in our country will think it's a great idea in another three to five years. But, really, it's like Nintendo is trying to chase customers away. There are already parental controls, so by making it needlessly difficult to purchase games that are geared towards adults, Nintendo is just sending the (admittedly true) message that they have no interest whatsoever in adult gamers. Unless you're under 14, really like virtual bowling, or are the kind of adult who describes things as "kawaii", there is nothing for you on the WiiU.
And, speaking as an adult who plays a shit-ton of 18+ games (on PC, thanks very much) 11:00 PM finds me either in bed finishing a book or out at the bar with friends if I'm off the next day. It's been many moons since I didn't have to be up and productive by 8:00 AM, and if I get less than 8 hours of sleep, I'm draggin' ass the next day. Besides which, how many people are going to be lining up for the opportunity to stay up later than they'd like to so they can have the privilege of buying a game from Nintendo?