Well, that's not quite true. I did a mod_handsfree (which is Bluetooth) module for FreeSWITCH a year or two ago. It's a hack, pretty rough, but I was able to receive and place calls from my iPhone with it.

I never submitted this to the standard FreeSWITCH tree because it's kind of hackish, it uses D-BUS, which is a pain to write in C, so it uses some helper python scripts that are called by FreeSWITCH for call control. Also requires a recent version of D-BUS which CentOS does not have, I believe I only found it available under Arch Linux.