You'd network your light sockets to get around the room-to-room issue. Each room would have a light bulb "port". Some simple communication could then figure out which room your in (similar to access-point hopping used in large wifi distributions)

I can see this as a potential technology for sideband data: stream the video over the light, but the control data would still go through WiFi (and then you wouldn't bog down your wifi with torrent downloads)