It’s a pretty interesting question to ponder. There are a lot of little sub questions you can associate with it such as “where will the graphical direction go?” or “Will motion controls remain the norm?”. In reality none of us actually know where the next Zelda title for Wii U (or 3DS) will truly be heading.
For all of questions, the biggest one I think to ponder on is the story direction. Skyward Sword was purposely made to be the first game in the timeline specifically to tackle unanswered questions and explain the origin of the Master Sword. It breaks all boundaries and sets a new precedent for the rest of the series existence, similar to Ocarina of Time when it explained the creation of Hyrule. So, what is the next great story going to entail?
I think it comes down to what Nintendo wishes to explain next. Many hardcore Zelda players are well aware of the various holes in the the timeline, and even beyond that, the lack of explanation for certain items. As an example: Where the hell did Majora’s Mask come from? As much as it seems unlikely we would get a Majora origin story, no one really thought we would get a Master Sword origin story either a handful of years ago.
So, they could easily go the Majora’s Mask route and explain the existence of Termina. Alternatively, they could fully explore the Sheikah and combine it somehow with explaining the Dark Interloopers. As you can see, there are a lot of ideas I can simply pluck off the top of my head. To many of the active theorists out there, I am sure you can come up with a couple dozen other stories. It is rumored, as an example, that Ganondorf will be in Skyward Sword but not really be relevant. You could easily have another game come out following Skyward Sword showing the Rise of Ganondorf to the head of the Gerudo’s, and show how he became “evil”. The possibilities are endless.
Of course in any future console Zelda we have to discuss controls, because Skyward Sword introduced an entirely new way of controlling Link. It’s even relevant for handheld Zelda, since the previous two we used the touch screen almost exclusively, but to do so this time would take away from taking advantage of the 3D top screen. One would assume in this case Zelda may return to more traditional controls, ala Ocarina of Time 3D.
Last but not least we have to touch base a little bit on the art direction. Honestly, I think every direction Nintendo has gone has suited that game just fine, so I have no particular wish list for it. I mean, would I love a Zelda with a full HD Twilight Princess style? Sure, but only if actually fits the game it is in. Likewise, I am just fine if TWW style comes back, or Skyward Sword gets another shot. As long as the style fits the game, I wont get angry. I’ve fallen into that trap in the past and have eaten my damning words every single time.
Where do you think Zelda goes after Skyward Sword?