If you're a developer, you've likely been chomping at the bit for Google to release the updated binaries and full device images after yesterday's Android 4.1.2 release. Just moments ago, Android maintainer JBQ placed 4.1.2 driver binaries for all maintained Nexus devices on the Google Developers site, as well as updated factory images (JZO54K) for the Nexus 7 and "takju" and "maguro" variants of the Galaxy Nexus.
These files are absolutely essential for tinkerers and developers wanting to stay on the cutting edge of Android, and Google has always been pretty on top of getting them out in a timely fashion. Just hit up the appropriate links below to download them.