So I downloaded and install KDE 4.0 stable on my Ubuntu Gutsy Gibbon install. Everything feels to be pretty new in the KDE desktop thanks to the spanking new Oxygen artwork. Plasma, the new desktop shell gives the desktop a clean look. All the KDE applications have gone in for a facelift.
Here are some screenshots of the new KDE release.
1. The start-up screen

The start-up screen of KDE 4.
2. The clean blue desktop – Plasma

The wallpaper is pretty but the KDE desktop could do with an option to reduce the size of the bottom panel. For me its a bit too large in height.
 3. The File Manager – Dolphin

Dolphin is the window manager included in KDE 4. Its pretty responsive and has all the functionality you will need.
4. Widgets in KDE 4

KDE 4 has widget support by default. Just click on the sign on the right hand of your desktop and it will give you an option to add widgets. Some widgets like Analog Clock, Digital Clock and Battery Monitor are available by default.
5. A tabbed Start Menu

Not sure how many will prefer a tabbed start menu but KDE 4 has it. Click on the different tabs like Computer, Applications and you have different menus displayed. The start menu also includes a search box like Vista which allows to type a few characers of the application you want to launch.
6. The Shutdown Screen

Finally the shutdown screen.
The puzzling thing is even if I click Log Out in the Start menu, it will still aks what I want to do Shutdown, Restart or Log Out.
P.S. – I found KDE 4 to be a bit buggy on Ubuntu. But nevertheless its ready to try.
So did you try KDE 4 ?