I just discovered this also, after somebody mentioned in this forum that the 1.5.5 update will allow Bluetooth headsets. I read the 1.5.5 release notes specifically looking for this feature. I thought that it wasn't there because it wasn't mentioned.
After I read that today in the forum I had to wait until a few minutes ago to try it because I haven't even bothered to carry my expensive new Bluetooth headset in my bag with me since it was such a pain in the neck to use with MacSpeech.
Thank you, MacSpeech, for allowing me to make my own choices. I'm not sure if this will get me back into using MacSpeech but it might. Thanks.