I'd like to see them mimic the feel and look of the Majora's Mask trailer, just with an older Link instead:
http://www.youtube.com/watch?v=blwR9rroBU0
That's fine is it not? It's still very clearly a fantasy world, yet it very eerie at the same time. I would like to have a Zelda game that "feels" that epic and dark pretty much all the way through.