It's a bug fixes and translations releases and is currently only in the proposed repositories for :self::precise:.
http://www.kde.org/announcements/announce-4.8.3.php :
"Today KDE released updates for its Workspaces, Applications, and Development Platform. These updates are the third in a series of monthly stabilization updates to the 4.8 series. 4.8.3 updates bring many bugfixes and translation updates on top of the latest edition in the 4.8 series and are recommended updates for everyone running 4.8.2 or earlier versions. As the release only contains bugfixes and translation updates, it will be a safe and pleasant update for everyone. KDE’s software is already translated into more than 55 languages, with more to come."
