I really really think that as much as many people want, Link being mute wont work for a movie. We forget that we never hear Link speak not because Miyamoto is crazy and adds weird aspects to its characters like being left handed, but he doesnt speak because that enhances the inmersion part, you are playing the character, you put the words in his mouth, and thus you relate to Link's character in a more profound level. While for a movie audience, the effect is totally the opposite, a mute caracter alienates the audience, they cant relate to it.
Instead of trying to shoehorn the story into a movie format, the movie should try to reflect as much as posible what made great the game. Zelda is in its core for what Ive read in Miyamoto interviews, about the kid who goes into the dark cave, and discovers a whole new world, and also a sense of progression and maturity. Yeah it would take an excellent Director and writter to achieve that, but if there arent any, better to not make the movie at all. (Miyazaki maybe? it would be perfect, although the movie would take several years to be made, but seriously, if its him, who cares?)
If the people involved in this game to film adaptations took seriously what movies and games are as an art form, we could have excellent results and not the atrocities seen in Uwe Bolls offerings.