8/4/2014 10am – Windows Phone 8.1 Update Cyan on my daughter’s non-Developer Preview Lumia 520.
8/4/2014 8AM - Update #4 – Nokia has yet to update their Update Release page HERE , but as of 8am EST the Windows Phone 8.1 Update (Cyan) is available and OTA on ATT.
This is currently installing on my 1020, my daughter’s 520, and my wife’s 920.
Most notable about this update, is how quickly it installs OTA.
Nokia has updated their phone release pages with a new article titled All-new Windows Phone experience: Lumia Cyan update. On this page you can read about all the new features in Windows Phone 8.1 such as Word Flow, Cortana and the Windows Phone 8.1 Action Center.
Update Availability has changed for the Lumia 1520 on ATT in USA to AVAILABLE.
ATT has updated their Software Update Page to include the update for the Nokia Lumia 1520. Read about that here Update the Software for the Nokia Lumia 1520
If you already have a Windows Phone 8, and want to know when the 8.1 update will be available, check out the official Nokia page: HERE.