If i understand correctly these BLE modes, to have the arduino "listen" for an ibeacon ( or similar) then you need a ble module capable of being set to "central" profile.
Something like this should do this http://redbearlab.com/blemini/
but any module with the CC2540 chip should work... im going to try some modules using this chip.
Did u seem my post here http://forum.mysensors.org/topic/709/indoor-ble-location-or-presence-detection
