Microsoft's hotfix to deal with an issue that is causing some Windows Phone devices to randomly reboot is now making its way to other Lumia devices in the US. We have confirmed the download is rolling out to Lumia 830 devices on AT&T and we have received tips that it is also being made available for the Lumia 1020, also on AT&T.
"We identified a problem in some versions of Windows Phone 8.1 that could cause a phone to restart periodically. A critical update will fix this problem. If you're unable to install the update or want to learn more, we can help you fix your phone."
In addition, we have received tips this update is going out to the Lumia 535 in Sweden and the Lumia 620 and 630 in India.
Update: We have received more tips the update is available for the AT&T Lumia 1520 and the Verizon Lumia Icon.
Thanks to everyone for the tips!