Update: Welcome back to Android Police. And now, here's an AT&T representative with a report on the recent Galaxy Note 3 software update.
A software update for the Samsung Galaxy Note 3 was made available for AT&T customers today. It provides general performance improvements.
AT&T's Galaxy Note 3 is barely out of the starting gate and it's already got an OTA update, probably fixing a few issues discovered as the Samsung phone was disseminated to a few hundred thousand users. The build number is JSS15J.N900AUCUBMJ5, and it should be heading out in waves to AT&T customers now.
There's no changelog available (from Samsung or anywhere else), but according to SamMobile, the newest version of the software has some minor software fixes including an indexing service crash when using a MicroSD card. The update's only real user-facing change is a slight adjustment to the included Samsung keyboard app, making the background a dark blue.
The update reportedly patches root exploits discovered in the initial software build, and may break root for those who have used methods like Root De La Vega. Consider yourself warned: hold off on the update if you want root privileges.
Update: The changelog is now up. It's not much really.