This latest version of Android is a rather minor update and brings improvements to the expandable notifications introduced in Jelly Bean. Notifications can now be expanded or retracted with one finger, as opposed to the previous two finger gestures. The usual bug fixes are included while some users are reporting that the user interface feels smoother. The landscape user interface has unsurprisingly not made its way over from the Nexus 7.
As is typical of new Android versions, you’ll be waiting at least a few months (or forever) before Android 4.1.2 arrives on your Android device. If you have a Verizon or Sprint model expect to wait a while as well.
KitGuru says: Android’s update system is fundamentally broken at heart but improvements are improvements.