HTC has released a firmware upgrade for the Cingular 8525 (also known as the AT&T 8525 now). This is not an upgrade to Windows Mobile 6 but it should offer bug fixes and general improvements. Unfortunately, HTC’s download page does not list what the update specifically adds or fixes. Fortunately, Engadget Mobile has done some digging and found the the upgrade will add a functional push-to-talk button, miscellaneous bug fixes from the 8525’s original firmware, and that love-it-or-hate-it AT&T branding.
Note: The ROM update will overwrite the current ROM image and to erase the partnership and all user data and programs on the 8525. Be sure to backup your data before doing the update.
Source: Engadget Mobile