AT&T and Google have released a brand new OTA Update for the Galaxy Note 2, but it won't change the firmware version or build number as it only brings updates for the already smartphone installed applications. The update is pushed Over-The-Air (OTA) and it can be applied from using the Software Update menu under Settings.
After you complete the update you will notice that the Android 4.1.2 Jelly Bean is still listed as the default OS. The JZO54K remains the default Jelly Bean build number only that it is a slight variation. It adds new features and tweaks that will bring a better and more stable Android 4.1.2 OS. The baseband of this new update is I317UCAMH3 while the kernel version is changed to 3.0.31-1363381.
This Android 4.1.2 OTA Update for AT&T Galaxy Note 2 packs 165MB and it mostly consists of pre-loaded apps updates along with stability tweaks. Go to Settings section and then access Software Update. Click the download and update button, wait until the new firmware files are installed. This is the manual method that you can use in case the OTA Update notification wasn't pushed to your phablet.
Make sure that during the download process of this new Android 4.1.2 I317UCAMH3 OTA Update your device is connected to a Wi-Fi network.
There is no official word from AT&T on the next Android 4.2 / Android 4.3 OTA Update, but we're expecting it to be available by the end of this year.
Did you get the update notification on your AT&T Galaxy Note 2? If you did, then tell us in comments if there are any visible improvements and how's the battery life.