You must be using firmware for the iPhone to work!
Is it 2.x or 3.x beta?
If it's 2.x then you'll need an adaptor to use with iPod stereo and use the controls. Otherwise you're stuck with mono and using it for the phone only.
Here's an example of an adaptor. The iPhone won't stream bluetooth stereo without on until 3.0 is released.
There are plenty of posts on pairing and using this with an adaptor in the bluetooth section of the forum, and it works great.
If you're using 3.x beta then you won't need an adaptor but Apple may not yet have fully implemented the A2DP into the firmware so the controls may not work as expected.