Just got my new iPhone 4 today, and after getting it activated and synced up in iTunes, I took it out to the car to pair it with my X920BT.
Paired OK. Hands free phone, BT audio and regular iPod music plays just fine. The only thing I noticed was that the phone wasn't charging. Pretty sure that my 3G did charge when connected. This was with a Pioneer CD-IU50V cable, BTW.
Anyone else?