While shopping for serial (CAT) Bluetooth modules, I came across a not-so-documented not-so-popular circuit sold as "XS3868 Bluetooth Stereo Audio Module".
The heart of the circuit is the OVC3860 chip, whose datasheet is hard to find, but specs look promising.
As I understand it, the XS3868 module is somehow what you would find inside a large Bluetooth headset for a cellphone, featuring playback buttons, volume control and a Li-xx battery charger. It runs off a 3.7 V Lithium cell and it can be controlled with AT commands via an embedded serial port.
Theoretically, if the resulting audio signal is not too distorted, this circuit can be used to build a wireless audio interface between a computer (Bluetooth master) and an RTX. This is most interesting for digital modes.
First tests may complete in late February 2014.
At about 7 USD, this is a worthwhile experiment for the future of HAM radio, HI.