I spoke last year with a Sierra rep about the "abstract" quality of Arcanum's visuals being one of its main limitations--hardly anybody in the game had a face. He agreed with me and said that the next game they were negotiating with Troika for would have a much improved engine.
Now Sierra has been sold again, and it looks like the Troika team took the idea with 'em. Can't say I disagree: their games need a more "in your face" feeling, and you get that most easily by giving faces to your NPCs.
I hear it's part of the package.