I started to work on this today to give an example, but man, more involved than I thought. I propose a complete rewrite of the desktop background code. Currently you can select to display and image and optionally have a gradient of some kind overlayed on it. This works for most people, but I like more control.
How about this. The desktop is actually composed of layers, much like an image in the gimp or so. There are different layer types. For example, there could be an image layer type. Here you select the image, or wallpaper, and then some other items like scaling types, position offsets, alpha blend. Then there could be another type gradient. Here you get your usual gradient options. It would be super damn cool if the gradient editor was like the gimp gradient editor. Ok, so now we have a list of layers. The backend code then loops through the layers one by one to generate a flat image to use as the background.
Another twist on this, which I think is the coolest, is plugins. I know it seems kinda overkill for a desktop background, but that allows for people to extend the options for the background very easily. Just have a few hooks. The GUI code for the options could be stored in the plugin. There could be an wallpaper loop pluging, image plugin, gradient plugin, coolGradient plugin, and so on...
The settings could be moved from the kdesktop to kbackground or something like that to avoid the clutter of the kdesktop configuration file.
I think this would be a great boost for KDE that the end user sees. This is something that windows does not have, gnome does not have... I do know that I have seen this kind of configurability in a Linux system at one time, but that was long ago and I have not seen it since.
What do you all think.