Actually, I've got it all figured out. We need to just get Nintendo to make a new game in the (very) strong vein of Majora's Mask, complete with modern production values and voice-acting, plus even more extra dungeons and side-quests. Majora is the pinnacle of the series from artistic, story and design perspectives, and the marriage of them in its case was simply divine. Bring back the quirky characters and expansive but non-essential side-plots, the weird inverted level designs, the transformation mechanic that brings vastly different play-styles with each form, and a villain that, if not new, is evil in a truly immediate sort of way.
I love what Twilight Princess did with its characters and presentation of story, but it was all too conventional. Ganondorf is absolutely amazing in his role, and for the first time we see him as a truly bad-ass icon of evil on par with Darth Vader, but he also seems arbitrary; similarly, the world design itself is much too standard and seems borrowed from prior games. As large as the world is, as well, it feels empty, even though there's probably more content available than many other titles in the series. I also can't discount The Wind Waker's successes, but it seems more like it takes a lot of the ideas from Majora's Mask, namely, strong characters and side-quests, and gives them a new face.
I don't want different for the sake of different, to the point where it's not Zelda anymore. I like Link, I like Zelda, I like Hyrule, I like my lakes and rivers and mountains, I like the Gorons and the Deku Scrubs and the Gerudos. Keep them all. They're gold. What we need, however, is more depth - a denser, more vibrant world with greater nuance in geography, art, gameplay and characters. Remember the Great Bay from Majora's Mask? In that (relatively) small area, there are a multitude of characters (Zoras, the old scientist, the Gerudos, and the effing beavers!), gameplay styles (stealth, several mini-games, traditional dungeon-diving, exploration), and visual interest (underwater, above-cliffs, beaches, fortresses, caves), all in equal proportion. That right there is an amazingly-designed gameplay environment for the player to run free in, and it can be made better still.
I really think that it can be done, but I fear that it won't be. Nintendo is capable of making truly the best Zelda game ever, and they probably know how to, but they're afraid. They have a mission in mind, one that involves bringing their best and oldest franchises to the new gamers that have adopted the Wii. And they know as much as I do (much more, I'd wager) that it's very, very hard to make something both deep and accessible, not just accessible to the average Joe who grew up with games, but to the person who hasn't played any games beyond Wii Sports. I don't doubt Nintendo's talent and I know they won't release a bad Zelda game, but I fear they won't realise all the potential laid before them by prior games.