You get a real conversation. The devs added some really nice speaking animations for your character, and you actually see more than the back of the head in several of the conversations. At the end of the DLC, you end up back at the Causeway after taking a "DLC Teleporter," though I think you can go mess around in the desert some more at the end of the DLC before leaving the area if you really want. I'm tired, so I didn't
I wonder if they added a slide at the end of the game for the DLC.