From the latest Nintendo Power:
Skyward Sword was just the beginning of some changes within the series.
Skyward Sword is a title where we took aim at all the conventions of the Zelda series. While that may have been difficult, I think that confronting those challenges resulted in something that has a great deal of value. When it comes to Wii U, we'll obviously want to add new elements that take advantage of the capabilities of the platform. I think using that as a lens through which we once again challenge the conventions of Zelda is more important than just making another Zelda game. With that in mind, please expect big things from the Zelda series to come!