Bluetooth on iOS has three different functions:
• user level features -- For example, headsets. There is no developer opportunity here (well, you can play audio that comes out the headset, but you know what I mean :-).
• networking -- You can establish a PAN network to other iOS devices with GameKit or Bonjour.
• accessories -- All Bluetooth accessory developers must go through the Made for iPod program. Once you have an MFI device you can then talk to it through ExternalAccessory framework. This is how iOS devices communitate with non-iOS devices, if they can at all...
<http://developer.apple.com/ipod/>
The 4S has BLE FWIW, which is in concert w/CoreBluetooth.
CoreBluetooth.framework is back