I think with BT you will have HID (mouse and keyboard) but you will lose COM port and file transfer and A2DP etc. Have you tried using your BT with these types of devices ?
Mouse and Keyboard still work right away as they did before SP2. Prior to SP2 I would use the Wireless Dashboard to turn on the BT settings window and use it to tell it to connect to the A2DP headphones as well. Since you asked the question, I tried the headphone process again but now although both the BT Settings window and my headphones are telling me they are connected in A2DP mode, no application will go to that "device". The apps remain associated with the IDT Audio Device. So unless I'm missing something, it looks like SP2 broke the stereo BT functionality I've had for the past two years. [Correction: All I needed to do to restore the A2DP functionality was to use the Control Panel/Sound to change it's default from IDT to BT when BT was in use. After that, disconecting or connecting the headpnones causes the default device to switch between IDT and BT, just as it did before SP2.]
I should mention that after disconnecting the headphones, I usually exit the BT Settings Manager which appears in the system tray after turning it on with the Wireless Dashboard.
[UPDATE] Of the msconfig items we've been discussing (QOQ Manager/Services, IDT Audio&Service, Toshiba Bluetooth Stack&Service) I have been running fine with only the IDT Audio stuff unchecked.