I want to be able to switch a call to my Bluetooth headset when I have the audio plugged in to my car stereo without unplugging. Now I have to either unplug before answering or talk with the audio coming out of my car speakers. Bluetooth remains connected, but N900 sends audio out over audio jack if plugged in. Is this possible?

Guess you'll have to watch the Pulseaudio way. Certainly there's not much information I've learned from their wiki and from other sources... Maybe IRC knows better. Anyway - it'd be good to have such a choice you're talking 'bout.
If you find such a inforamtion - please, write it here, or let me know somehow. thanks