Sooooooo I finally release BlueDrift a Bluetooth OBEX file-transfer sniffer that is based on the frontline bluetooth sniffer firmware for CSR bluecore-4 chips. The original slides from 2007 had the awesome title: More Fun with Blue Radio Waves. The project and it's name was inspired by of Driftnet.
You need the Frontline firmware image in order to turn your Bluetooth USB adapter into a sniffer. Don't ask me for this firmware, buy it!