I feel like the Zelda team can go anywhere at this point (not like they haven't before :P). It's kinda like asking what would you do after releasing classics like OoT, Sgt. Pepper, Terminator 2, Pet Sounds, Toy Story 2 (and 3), etc.
I wouldn't mind whatever they'll do next with Zelda as long as the quality is maintained like it has been for over 30 years. And in a way, they've went back to basics with BoTW, being influenced by the original Zelda and it's open world concept and expanding upon it in 3D and HD. I just hope that we don't go overboard and claim or expect "better than BoTW" or what not because it sets an unfair precedent on future games of the franchise. Though then again, we've been comparing previous games to OoT so I'm probably making a moot point :P