KDE is delighted to announce its latest set of releases, providing major updates to the KDE Plasma workspaces, KDE Applications and KDE Platform. These releases, versioned 4.6, provide many new features in each of KDE's three product lines.
What is new in KDE 4.6
You can check here for all the changes in KDE 4.6 from here
Install KDE 4.6 in ubuntu 10.10
Open the terminal and run the following commands
sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt-get update
sudo apt-get install kubuntu-desktop