Android 4.3.1 Jelly Bean is likely a minor update with the usual stability fixes and bug patches. What’s interesting however is that Google has already launched a few of those update and fixes without incrementing the version number, so this likely has some deeper changes that we’re yet to explore.
The update has rolled out over the air and should arrive to your device soon, if it hasn’t yet. It weighs 9.42MB and keeps the radio version of the device the same.
source: Android Police