KDE 4.6 desktop environment provides you with many new features to plasma workspaces, KDE applications updates, and KDE platform update. Many features mentioned at KDE 4.6 announcements such as
How to install KDE 4.6 on fedora 14 Laughlin
These instructions down there you can use for install KDE 4.6 or upgrading your current version of KDE desktop to KDE 4.6
Download KDE repository from Here.
Paste KDE repository to repositories directory
yum install @kde-desktop
[note]Require administration privileges use “su”[/note]
It will take some time for checking current packages you already have and current version of KDE desktop you have, or install it if you don’t have it.