We can't know what resources it'd eat up or if VO's preclude a larger world, vehicles, etc. If it really does, then I'm with Wisdom and I'll reluctantly play a dumb mute. But no voice goes down a lot easier in FP than it does in TP. My guess is we get one male and one female voice. That's not pushing resources given how many RPG's routinely do that. And there is the fact they made TW2 for so bloody cheap.Very much this. I loved Adam Jensen's voice and Geralt's voice and Agent 47's voice...but if you'd offered my more content to DXHR or Witcher 2 or Hitman Blood Money, I probably would have taken you up on your offer in a fast instant. Probably.
For an open world game, I think a core of voice dialogure would be fun, but to voice every line your character might speak in two sexes...I just can't see that not cutting into content or gameplay options.