Me respondo a mí mismo: No se puede, de momento. La misma pregunta está en varios sitios, sin respuesta, aunque he encontrado que uno contactó con HTC y le dijeron que todavía nada: "I would like to know the same thing. I contacted HTC and asked whether the HTC Magic (G2) supported rSAP. Their answer was that there is no rSAP support in the current Android (V1.5) software. They are expecting this feature in future versions of Android. The current bluetooth support in the HTC Magic is: Bluetooth v2.0, headset support only."
http://www.mail-archive.com/android-.../msg10268.html