Any resolution to this problem yet? I have the same issues. It seems to be a problem only when bluetooth and wifi are both in use. I have bluetooth mice and keyboards dropping out all the time as well as a bluetooth speaker that causes the wifi to disconnect every time I turn it on and it connects to my surface. This is really annoying when I'm trying to stream a video and actually hear it through my bluetooth speaker rather than the anemic surface pro speakers.
Any help would be greatly appreciated--other than rolling back to regular Windows 8.
Thanks,
Tyson