Is it possible to provide a BLE service on Mac OS X?
From the CoreBluetooth docs found here http://developer.apple.com/library/mac/#documentation/CoreBluetooth/Reference/CBCentralManager_Class/translated_content/CBCentralManager.html it looks like you can just scan for and connect to peripherals. I am looking to act as a perisperhal.
This is possible now with OS X Mavericks (10.9). The same CoreBluetooth CBPeripheralManager API for iOS is available on OS X.
An example can be found here.