Playable Zelda, Impa, Linkle (maybe rewritten though), new awesome female character: HELL YES
Female Link (which would also represent a push more towards Link being an avatar): Big fat Meh
This. (sans the last sentence, which i left out in the quote)
Saying Link is an avatar, that hasn't been the case since the 3D games. If Link is an avatar, then i'd want more things i'm able to change, see Commander Shepard.
Pokemon isn't a valid example, too. Because you choose between two different characters, and the not chosen char is added as an own character in the games.
Just because a character doesn't have a incredibly fleshed out personality and/or story, doesn't mean that there should be a gender option ... see Gordon Freeman, who'd call shallow in terms of characterization.
Therefore, if Nintendo wants a game with a playable heroine, give me a game where i play as Zelda, Impa or a new character.