Almost.Â There will be new headphones which are similar to those of current iPods [1/29/07], but which incorporate a microphone. Calls can be answered and ended by squeezing the microphone. Wireless earpieces that use Bluetooth technology to communicate with the iPhone will be sold separately.
UPDATE: Yes, as of the release of iPhone OS 3.0, the iPhone now supports A2DP.
Many of today's newer wireless devices (i.e. the Samsung Blackjack) support A2DP audio output. A2DP audio devices, such as stereo bluetooth headsets, offer high quality listening ability without those nagging wires. As the iPhone is birthed from the iPod, and is undoubtedly the most music oriented phone ever to be developed, surely the iPhone supports A2DP, right?