Bluetooth support will consist of two main pieces: The RFCOMM communications layer (realized as a comm tool) and the Bluetooth Setup application. The RFCOMM layer will handle HCI and L2CAP to provide a serial port over Bluetooth. The Bluetooth Setup application will handle the rest, including discovery and pairing. It can actually be implemented in NewtonScript, I'll have to see about that.
There is also the area of Bluetooth by-products. At the moment, I'm thinking mostly about location-based services. It would be quite simple to let the Newton scan its Bluetooth neighborhood upon wakeup to determine where it is at the moment. It is also easy to advertise its presence by simply being discoverable for some time. All this could be done at the NewtonScript level.
Unfortunately, the current architecture restricts usage of the serial port to one program at a time. As an example, a location-based service would have to share the port with the receiving transport and the sending transport (Neo). Unless I figure out something smart such as multiplexing at the Endpoint level...