I don't recall them asking us if we wanted voice acting. On his blog, Swen did pose that question about Dragon Commander, but in this game, they've been clear from the start that any voice acting will be restricted to only a few important characters.
I think there will at least be some simple cinematics closer to the ones in Dragon Commander. Maybe not the fancy ones from Divinity 2, which while awesome-looking, were probably somewhat expensive. In-game it could be hard to put them in because of the co-op. In theory, your partner could be halfway across the map in combat with a flesh-eating beetles at the time.
