Yes, the voice acting is the last one to implant when the script of the game is in finalizing as it has been done before with Divinity: Original Sin (I think it took them 6 months when the game was still in development but the script of the game were finished). Remember that was only for the script above NPC's and player heads, though in the Enhanced Edition it's fully voiced.
I think we do not need to go much in detail as it's pretty much Swen said that there will be "voiced" but the speech above the characters head, and still unsure about full voice acting yet. I am also sure it's the most popular topic to discuss as these type of games does have allot of dialogue and most people sometimes want to chill and not strain their eyes too much on the screen :P
