The past few hours have been quite exciting for Nexus device owners. Earlier today, Google started rolling out the Android 4.2 Jelly Bean OTA to the Google Play variant of the GSM/HSPA+ Galaxy Nexus (takju). The OTA update file was shared with us by XDA Senior Member HAKA, along with installation instructions for all GSM/HSPA+ variants of Galaxy Nexus (yakju and yakjuxx). The method involves first installing the latest 4.1.2 takju factory image on non-takju devices, to be able to install the 4.2 update. However, there is no longer any need for that.
Hours ago, Google uploaded Android 4.2 factory images for not just the Galaxy Nexus, but also for Nexus 7 (both WiFi and GSM/HSPA+), Nexus 10, and Nexus 4. While an official yakju image for Galaxy Nexus is still not available, the takju factory images can directly be installed to any yakju or yakjuxx device.
In case the code names have your mind in a jumble, takju is the Galaxy Nexus variant sold by Google in the US Play Store, which comes with Google Wallet pre-installed. Yakju is the exact same device sold internationally by Google, but doesn’t ship with Google Wallet. Yakjuxx is the exact same device sold internationally by Samsung. Google directly updates takju and yakju, while yakjuxx devices are updated by Samsung.
You can download factory images for all these devices at the Android Developers Website.