If your HTC EVO is running software version 3.30.651.2, which is only supposed to be available to newly manufactured handsets, then you've got yourself a new OTA update to install today.
Version 3.30.651.3 fixes a power cycling issue that is said to occur when accessing the camera in apps like Qik and will not be rolled out to EVOs running 3.29.651.1 or any other version that isn't 3.30.651.2.
Those who have flashed custom ROMs based on 3.30.651.2 will receive the update, but considering that I had to do a Nandroid restore to get my EVO functional again, I would advise against installing it unless your phone shipped from the factory with 3.30.651.2. Your mileage may vary.
Did anyone get it successfully installed?