i'd like the ruppees i get to actually be worth something. since OOT they mainly just sit unused in my wallet.
a first person zelda would be no good. it would be like oblivion with more suck. OOT WW and TP have shown that third person zelda is a great way of doing it, the change, i think, should be in the game.
in that sense, robbing from Oblivion (or western RPG's in general) wouldn't be a bad idea. a huge open world, more towns/cities, etc. don't make exploration/travel linear. i'm not saying link should do quests with the assassin's guild, but not all items/upgrades need to be dungeon based either.
dungeons are fine, but i agree with the block pushing puzzles. sheesh. one of my favorate parts of WW was sneaking into the castle and hiding under the jars.
somewhere else WW succeeded was in the story. the bad guys took your sister! this wasn't some existential desire to save the world as a whole, this was a quest to get your sister back. you just happened to save the world on the way.
if they make hyrule a living breathing place, then even if, as Ian pointed out, you already know it, it will still have that something that makes you look forward to exploring it.
oh and having a real threat of death wouldn't be bad. not saying everything should be boss hard to fight, but it would be nice to actually be worried some of the times...