(Megaman)I have wanted this exact thing for years.
As for my thought on the topic...
...but not just a bland gender-swap where you're saving Link, so this picture may not necessarily reflect what I'm thinking about. Also, don't say thing one about that godawful CD-i game. ...either of them.
Zelda, commonly being the keeper of the Triforce of Wisdom as opposed to Link's Courage, would likely take a different approach to a world-spanning epic, employing less combat-oriented tactics and maybe more diplomatic approaches to problems. When things turn ugly, she has magic to fall back on primarily and when all else fails perhaps some lighter arms than a broadsword and shield. Maybe put a greater focus on puzzles and thinking rather than quick reflexes and combat though. Taking cues from Smash Bros. and the upcoming Hyrule Warriors, we've seen Zelda depicted as fighting with both Bow and Rapier so maybe something in that style. And of course I'm a bigger fan of the classic 2D games than the newer 3D titles, so I'd like to see something that played like Link to the Past more than say Ocarina of Time.