Couple of days after Google started rolling out the KitKat OTA update for the Nexus 7 (2012/2013) and the Nexus 10, the company has released the factory images for the devices as well.
Surprisingly, the company has also released the factory images for the Nexus 4 even though the OTA update for the device is yet to start rolling out. So, if you are an impatient Nexus 4 owner, you can get KitKat on your device right away by flashing the factory images manually.
The updated binaries for KitKat have also been uploaded, so custom ROM developers can update their ROM to include them.
Factory images are mainly useful for tinkerers who want to restore their device to stock after flashing numerous custom ROMs and kernels. The Nexus 5 (hammerhead) KitKat factory images were already available for download.
The factory images for the Nexus devices can be download from here.