I don't think Malestrom's definition is wrong, necessarily, but I don't feel it encompasses the true Zelda experience either. Malstrom speaks of the dichotomy between overworld and dungeons, but as many people have pointed out that is a line that has long been blurred. Even the original Zelda did not limit it's available "upgrades" to the dungeons, and the movement towards more integrated dungeons would serve to further break down that distinction. I think that is the proper way to move the series forward, by the way.
Anyway, Miyamoto once said the essence of Zelda is a child's desire to explore the world. I think that should be taken more fully into consideration by the design team. I can imagine a world where the player can truly explore what he wishes, in what order he wishes. Start of easy, with only three dungeons, and expand it from there. Perhaps they could also make use of a dynamic storyline where events of one "dungeon-arch" affect those of the others.
Making non-projectile items more useable in combat would also be a plus (think of the Hammer in ALttP). That, of course, would likely be addressed in Zelda Wii, as pointed out by the OP.
More than anything, though, I want Aonuma and the Zelda team to do whatever it is they wish. Don't listen to fans (certainly not me)! Twilight Princess was so hampered by fans' requests that in many ways it felt like a step backwards... Please don't make the same mistake again.
