Just noticed that you can use the file browser to open mp3 files on the Blackberry. Listening to a tune off my Bold 9900 on my Logitech Z515 Bluetooth speaker through my Playbook right now.
As a side note - this means that the A2DP AND the Bridge are working at the same time. I'd say that's a pretty damn stable Bluetooth connection. Just for entertainment I just did a BT sync with Desktop Manager while doing the above. Not a skip, hiccup or glitch.
Whoever handles the bluetooth stack at RIM deserves a medal. Rock solid.