Last year's Zelda HD experience was certainly graphically impressive, but as always Nintendo was keen to stress it was just an example of what's possible; we know from past experience Zelda tech demos often vastly differ from the finished product. Nintendo's main man Shigeru Miyamoto told Entertainment Weekly there are various Zelda Wii U experiments on the go, but nothing he's ready to talk about.
Miyamoto discussed the increasing trend towards "more casual experiences", musing on how Zelda might fit in:
But one thing that’s interesting is we’re seeing how the way that tastes are broadening in video games and you have some people who prefer more casual experiences, and you have some people who prefer sort of those more in-depth experiences. Obviously, as a company that’s been making games for a very long time, we tend to be more on the deeper, longer game side of things. But really what we continue to ask ourselves as we have over the years is, “What is the most important element of Zelda if we were to try to make a Zelda game that a lot of people can play?”
Miyamoto and team haven't settled on an answer yet:
So we have a number of different experiments going on, and [when] we decide that we’ve found the right one of those to really help bring Zelda to a very big audience, then we’ll be happy to announce it.