I have written a program that should work with any WM 5.0 phone. It will transfer the caller announcement to your BT headset.
http://www.ppcgeeks.com/transfer-cal...set-t1559.html
That is the link to the fourm I started here on it, and it also gives you a link to the place where I first started to develop the program for any additional information you need.
Enjoy!