Last nights announcement that Google would be releasing a security update for a range of Nexus devices has come through this morning with factory images being posted to the Google Developers page.
Of the devices promised, only the Nexus Player factory image is missing, with updated factory images with build # LMY48I now available to download for the Nexus 4, 5, 6, 7 (2013) Wi-Fi, 9 and 10. The Nexus 7 (2013) LTE edition has been left out again, though the Nexus 9 LTE has been given an update. So far no sign of OTA updates for the devices have appeared, but they should begin arriving in the next 12-24 hours given the promises made by Google.
The LMY48I binaries have also been updated for developers wanting to get the latest drivers for their builds, so you can find them as usual on the Google Developers site too.