If they want to incorporate a spoken Hylian language, that is actually a coherent language instead of random gibberish, I'd be fine with that. It'd save on translation costs, as it would only need to be done once, and it would flesh Hyrule out more as a fantasy setting.
Other than that, I'm not a big fan of voice-acting. Most games I've seen voice-acting in, it's either been terribly-executed, or they spend so much development getting the voices right that it cuts into the rest of the game, dragging the rest of it down with it. Not to say that there aren't examples of it done well, I really liked the voice-acting in Metroid Prime 3, and that was a series that went from no voice-acting to selective voice-acting. So it CAN be done right. I just don't see why it's such a big deal, I fill in the voices of the characters in my own head anyway, so voice-acting is kinda needless in this case.
If they actually do something useful and world-building with voice-acting like with that spoken Hylian I was talking about earlier, then yeah that sounds awesome. But if it's just to please the fans or to "catch up" to other games then I don't see the point.