I think the storyline might go for an improvement and I have this in mind:
You know how in the Zelda games, Link goes in a dungeon, gets a tool, kills the boss, then gets whatever he came in for, and only a few people, or perhaps most of the people from the area where you found the dungeon, notice and praise what you did?
I'd like the next Zelda games to expand on that, instead of a specific group of people knowing what Link did, have virtually everyone who Link has encountered in the game to make clear they know the heroics he does, it can help give the player the sense of being the hero, it worked for me when I played Fable 2 and Mass Effects 1 and 2.
I know this is Nintendo we're talking about, not Loinheart or Bioware, but I think you get my point.
Another thing is I'd like the option to continue playing a Zelda game even after finishing the main quest, so I can finish the optional side quests that Zelda games often include.