I'm thinking, if there were to be a TWWHD stage it would be a new version of Pirate Ship, like "Pirate Ship HD" or something. Same basic layout, but new graphics based on TWWHD and new hazards. A relatively simple to make new stage to make, which would help pad stage roster numbers. That, Skyloft, and Temple, I could see that being Zelda's stage representation.
But I think at this point the stage I want to see the absolute most is a new Donkey Kong stage. I don't even care what the hell it is at this point. We're about a month out and we still haven't seen a new Donkey Kong stage. In fact, in terms of new content, Donkey Kong has gotten dick. The only new Donkey Kong feature in the 3DS version is a new song. No new character, no new stage, no new item, and not one single fucking Assist Trophy period, anywhere. The way franchise representation has been handled this go around has been pretty eye-opening, in a negative way, to say the least.