14 DAY TRIAL // Just a few days ago, the Android 4.4.2 OTA update for the Nexus 7 (both 2012 and 2013 models) and Nexus 10 was spotted into the wild.
But for those who didn't get it so far, Google has made available the factory images and binaries, so you can download them right now. Note that you’ll need to have Android 4.4. or Android 4.4.1 installed in order to upgrade to the latest build.
Once you have successfully flashed the proper Factory Image to your device, Google advises you to lock the bootloader, advocating for safety.
Factory images are important to those who plan on tinkering with their devices and need a safety net to fall-back onto, in case something goes wrong. As for the source code, it will surely be picked up by developers working on custom ROMs, with CyanogenMod and OmniROM leading the way in this department.