Wireless headphones are great in theory, but in practice they tend to be bulky and not really worth the snipping of wires. The problem is that you need to cram a Bluetooth receiver into something that's supposed to comfortably rest on your ears, which isn't that easy to do.
Apparently Sony realizes this, so they're working on a technology to send music signals directly through your body. Because the signal is sent through a tinny electrostatic charge, they can only fit 48 kbps into the transmission without it becoming a painful experience. Somehow I think that some audiophiles would love to brag about being able to withstand the pain of transmission to get hott 320 kbps quality listening, but who knows if Sony will be up for marketing to the masochists.
Body-wired headphones [New Scientist]