To connect to my MP3 player, XM Radio, or other audio device without Bluetooth, I currently use a Bluetooth Dongle Adapter device similar to this: TaoTronics (click here)
Since I would like to have my wife listen to the same audio I'm listening to, I am thinking I could use a Y-adapter from my player's audio jack allowing me to connect two Bluetooth Adapters so we can pair both headsets at the same time. Hopefully this will get us through until Sena releases the A2DP hub allowing two bluetooth connections, sometime around mid 2012.