Pioneer's Power Line Communication Music Tap can stream your tunes all around your house using the power lines, but the features don't end there. The main base station, the XW-PSS01, has two USB inputs and three auxiliary inputs and supports MP3, WMA, MPEG-4 and AAC. Plug the base unit into the wall power outlet and supported speakers throughout your home will recognize that the unit is plugged in. The supported S-speaker even includes a motion sensor that will begin streaming music from the base station when a presence is detected in the room and it will turn off after a set period of inactivity. This system is just dying to be paired up with a satellite radio receiver, in my opinion. It should be available mid-March. Pricing information has yet to be announced.
Pioneer Music Tap sends audio to speakers through your house's wiring [Ministry of Tech]