Today Sebas and I put the finishing touches on a couple of neat features and I felt compelled to share them with you via screencast because together they are just that cool! ;)
The first feature, which is mostly thanks to Sebastian (I just did some janitorial work on the patch), is the ability to drop remote content onto a Plasma::Containment such as a desktop activity or a panel. Plasma, via KIO, tries to figure out what you are dropping and then offers a set of matching widgets, if any, to create for that content.
Dropping HTML? Get a web browser widget or a link to that page. Dropping an image? Get a picture frame or an icon pointing to that image.
What happens when you drop something that one of the wallpaper plugins understands? Well, you get an entry for that wallpaper in the resulting menu of choices. That means you can drag an image from a remote system, say off a webpage, and it will download it and set it to your wallpaper. Each wallpaper plugin can define what kind of data (mimetype) it can accept, so this feature is completely dynamic depending on what wallpaper plugins you have installed. That's quite a bit more flexible than what we had in KDE 3, where the drop file types were hardcoded inside of kdesktop.
So that's one new and cool feature (remote content drops) combined with one (improved) feature many people have been asking for (wallpaper drops).
Interestingly, I told several people (including people at distributions) how a patch to do the wallpaper drops would look like. In spite of many people insisting that this feature was of imminent importance, nobody sent in a patch even though the "how" was spelled out in detail. Finally, I got around to implementing it at Tokamak 3 one evening after someone mentioned it on IRC. I was too tired to work on anything serious so I figured I may as well implement wallpaper drops. The "moral" of the story is that I'm happy to help you with the "how" of writing a proper patch for a given feature, but if you don't do it then you'll have to wait until it rises to the top of my priority list which may be, depending on the feature, unpredictable.
Without further ado, I give you "Dropping Remote Images To Set Your Wallpaper" via blip.tv (where there is also an OGG video version available and waiting for you):