HTC posts an update to the Cingular 8525
No, it’s not WM6, but it is a ROM upgrade for the 8525 (AKU 3) that adds Push-To-Talk, among other things. This will upgrade your 8525 to:
ROM Version 2.15.502.3
ROM Date 04/09/07
Radio Version 1.40.30.00
Protocol Version 32.73.7020.16H
http://www.htcamerica.net/support/8525/software-downloads.html