I'm not one to hold much value in a retailer listing, but this is Amazon France. Amazon France is that guy who spoils everyone's surprise party, and lets it slip that you are having an affair or cheating on your taxes. And from my experience, they're usually right on the money.
There's also a lot of what I like to call 'no shit factor' here. As in 'no shit' Nintendo is going to make a Mario Kart for Wii U, and 'no shit' they're going to make a Zelda game for the Wii U.
Ah, see! I just pulled an Amazon France and spoiled the surprise for you.
These games are likely a ways off, but I'd gather that they're in production at this point, with Mario Kart U hitting first around June, then Zelda around holiday 2013. Sound accurate enough? I'll check back in a few months to see if my Magic 8-Ball was right.