> If you're using DC to transmit the same amount of power, you'll probably be using similar voltages (otherwise you're going to need thicker cables).

A good point - I guess I'm mostly thinking about the volume of things in the house that don't really need access to even a fraction of the 2.4kW available; having moved from incandescent bulbs to LEDs, I've got a bunch of unnecessary power supply and per-bulb transformers, for example.