With the Android 4.2.2 update finally rolling out for most Nexus devices (minus Sprint / VZW GNex), Google has posted factory images of each on the Nexus Factory Image page. These images are useful for flashing your Nexus device back to stock, whether to get an OTA update, or fix that brick you just caused.
These images are for the Nexus 4, Nexus 7 (Wi-Fi and 3G), Nexus 10, and Galaxy Nexus (Yakju / Takju variants). If you want to see what's new in Android 4.2.2, check out our post detailing some of the changes. For a deeper dive, take a look at the developer changelog.