Imagine something like this next to a light switch in everyroom.... but instead its the iPod UI with a nano screen. Not only will it act as a dimmer switch, but it can do all things you would expect it to
Dim lights
Adjust volume and change music, play list, stream
Mated with a thermometer, adjust heat/cool
With networking over the wiring or WiFi
In package adaptor
In location change out (replaces the single pole switch)