EA is essentially meant for play testing various mechanics and features of a game. Voice acting is one of the areas that generally needs little to no testing - record, install and go. I would expect additional voice acting to be at the bottom of the list for EA - something that can easily be handled closer to full release, rather than early on, when the vast bulk of time needs to focus on things that actually need testing and development.
I'd much rather see additional levels, classes, races, spells, feats, skills, items, combat actions, camera and movement mechanics, and a boat-load of other features tested at this stage in development, than more voices.
