Rydah - I tried assigning it as Stereo Bluetooth, but that works intermittently at best (1-2 of every 10 times). After asking a bunch of people for help, somebody finally pointed me to this program:
http://www.freewarepocketpc.net/ppc-...oggle-1-0.html
It gets the stereo Bluetooth audio to switch to my SP700 on the first try about 90% of the time, so that's obviously a big improvement. If you do install the program, just be aware that it doesn't actually display anything when you click/run it. The only way I know it works is hearing a confirmation beep and then (obviously) the music.
Just like everyone else, I still have to ask HTC, "Why the f should I have to download an additional program?" -and- I'm still up for any other solutions/suggestions people have!