I see a popular opinion on this thread is to bring back Ganondorf. While I agree that Ganon has played a huge part in LoZ, I would love to see a villain whose power seems limitless. Ganon has a few things that are traditional for him, such as turning into a boar and that signature sword of his. I would love to see a completely new villain who, of course, would crave power and and enslave the races of Hyrule. But I would like to see a Zelda game in which, for a good portion in the beginning of the game, you are simply adventuring around. Possibly, Link could want to become a Hylian Knight and the first portion of the game is training and passing different trials, when all of a sudden, Link is thrown into the duty of a knight prematurely, where he must quest for (blank) so he can destroy the evil lord (blank).
I have a notebook labeled "Zeldeas" full of ideas for items, upgrades, dungeons, you name it. I've been brainstorming ideas for a couple months now, just for fun. I must say, not to point out the obvious, but I love Poes. There is such a wide selection of what you can do with them. They are the spirited embodiments of hate. If the new WiiU Zelda goes with a more TP shaded world, I would love to see another dark and mysterious title such as MM. Behold a Zelda game where the plot is thus:
Hyrule is in a state of much disarray, where different clans are having difficulty cooperating with one another. This difficulty soon blossoms into what one can only call hate. Through all of this hate, the four Poe Sisters gain power. They gain so much power, in fact, that they soon find themselves collaborating to revive the evil lord (blank).
This of course is only an idea, but I thought it would be a great way to show LoZ's dark side. Save the happy-go-lucky graphics for the 3DS.