No, the Zelda franchise does not need voice acting. It would ruin the brand. Think about what voice acting has done to the Final Fantasy franchise. If you don't get good voice actors who are consistent and believable, it really ruins the experience. Seriously, listening to Hope and Vanille in FF13 was so horrible, I just don't want them to input a fairy for Link who sounds like Hope, someone who sounds whiny.
In my opinion, the voice work done for Fi was incredible to me, it really doesn't need to go beyond that. If devs don't want to splurge on good voice actors, the game gets ruined pretty easily. Only reason I would go for Legend of Zelda having voice work is if the actors for it are exceptional and make me think "This guy is Link, or Zelda." Otherwise, him not speaking, and Zelda's acting is as believable as anything.
Zero Escape: Virtue's Last Reward = best game ever made.
