Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of KDE Plasma, please access the KDE tag and open the latest article (the one on top).
The latest installation instructions for KDE Plasma
Hello Linux Geeksters.The KDE 4.11.2 desktop environment has been released today. Among others, it brings improvements for the following apps: KWin Window Manager, Dolphin file manager and Kontact PIM suite. For more information, see the changelog.
This release comes only with some bugfixes and translations, so no new features were added to KDE 4.11.2. It will be soon added to the Kubuntu Backports Repository, in order to be easy to install on Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal, Ubuntu 12.04 Precise Pangolin and derivates, including: Linux Mint 15 Olivia, Linux Mint 14 Nadia, Linux Mint 13 Maya and others.
How to install KDE 4.11.2 on Ubuntu and Linux Mint:
$ sudo add-apt-repository ppa:kubuntu-ppa/backports
$ sudo apt-get update
$ sudo apt-get install kubuntu-desktop
How to update the existing KDE version to KDE 4.11.2, on Ubuntu and Linux Mint:
$ sudo add-apt-repository ppa:kubuntu-ppa/backports
$ sudo apt-get update
$ sudo apt-get upgrade