I know that A2DP has been announced as an official feature of iPhone OS 3.0, but I'm not sure exactly what that means. I understand that means the iPhone will support stereo bluetooth audio. What I don't understand is if that means if the iPhone will actually be the bluetooth transmitter as well? Currently if you buy bluetooth headphones, you still need a bluetooth transmitter such as the Sony Bluetooth Wireless Transmitter (http://www.amazon.com/Sony-Bluetooth-Wireless-Transmitter-Black/dp/B000XRW09Y/). With A2DP in the iPhone 3.0 software, will we be able to just buy bluetooth headphones, and have the iPhone be able to transmit the audio itself, or will we still need a transmitter? Thanks.