I posted before that I tried pairing with the 2005 Range Rover and it worked. Since I've taken delivery of my vehicle I can now update what features are supported and what is not.
Supported features:
Make a Call
Receive a Call
Reject Incoming Call from display only, not steering wheel
End active call

Unsupported Features:
SMS via touchscreen
No missed call display on touchscreeen
Phone Book
Last number redial (though I found this to work, it redials whatever is on your phone if you push the send button without entering a number on the car touchscreen)
Hold/Unhold
No display of signal strength

The car and the 6600 paired fine and it works as advertised. I had one instance where the caller stopped hearing me, not sure if it was due to the Bluetooth or their phone.

With respect to my Toshiba M200 Tablet PC with the Bluetooth module, it works great. My Bluetooth drivers are from Toshiba (Apparently you can use the ones from Microsoft also). I'm able to performs wireless syncs without issue. I'm also able to use the internet on the computer via Bluetooh with WinModem and that works great.