I agree with illmatic. I don't agree with link having an actual voice for these reasons:
A voice gives him a personality. Personality isn't bad of course, but one of the themes of the zelda series and the themes of many nintendo franchises in general, is that you don't just play the characters -- you ARE the characters. Miyamoto has set up the storyline to get you immersed in it, and if he defined everything about link's character, it would feel more impersonal, at least in my opinion, to play as link. I like the fact that Miyamoto gives you choices and likes to inspire imagination in the players of his games.
Without link having a voice, you get to choose and imagine many things about him. That's what makes it fun -- putting yourself into the character, not simply playing as a pre-defined character.
Another reason why link, in my opinion, shouldn't have a voice; the text boxes. Seemingly not a big deal, but I prefer to read at my own speed what the characters are saying, and i'd rather not just hear it. Obviously there could be both text and written dialogue, but I prefer text.
Besides, the zelda cartoon was bad enough in terms of dialogue ... I don't want to hear link say "excuuuuuse me, princess" anytime soon.