Korean company Waveon is now shipping the AON MCH-501U, USB headphones that can handle Dolby and DTS 7.1 surround sound. A convenience is the way the headphones draw their power via the USB connection, so there's no power supply necessary. There's an in-line controller as well, and if you have compatible sound sources, you'll be able to enjoy full 7.1 sound without having to buy a fancy sound card.
Our Korean is a little rusty, but we're guessing that the MCH-501U is selling for around $90 in Korea. No word if they will become available in the United States anytime soon.
Waveon offers AON MCH-501U USB headphones [ bergizmo]