I installed the update, already running 8.1 here but Windows Update offered it anyway.
After the several reboots for firmware, it had rolled back the display driver so I reinstalled it and rebooted. It seemed to have left the WiFi and Wacom drivers alone.
I would have preferred to download the zip like I did for the August update, so I could choose the individual pieces, but it's not yet in the download center. Would also be nice if the release notes page was a bit more detailed.