This is an idea of adding more content providers to KDE wallpaper properties.
Now, when you right-click on your desktop and select Configure Desktop, a window appears. It has a "magic" Get New Wallpapers button, which fetches the list of wallpapers from KDE servers.
It would be great if the default KDE installation provided also different sources, like the absolutely amazing caedes.net
It should be quite easy to implement, yet providing a useful feature for end-users.
The default installation should have only a few providers integrated, to avoid the feel of being lost ;)