With Apple pushing for a wireless audio future on their iPhones, one scenario holding them back for a (probably small) group of people is with their own Garageband app and similar apps. Garageband requires wired headphones to hear a track while recording a new track on top, in order to stay perfectly in sync. If you try with bluetooth headphones, the app will tell you to plug in wired headphones. I wonder what solution Apple will offer if any at all.