I just hacked together a simple program that is (more or less) able to randomly display the images taken from DA's RSS feeds as your desktop background.
The main problem is that DA's RSS feeds are pretty poor, but beside that, it works.
The program is written in VB.NET (the sources are available) and therefore the .NET framework 2 is required. I was able to test and run it succesfully on XP Pro SP2 and Vista Ultimate. Installation is not required, just unzip the two files in a folder (do not put them on your desktop, because it will create quite a lot of temp files) and run it. Bear in mind that this is the very first release, so it will surely contain lots of bugs.
Ok, 'nuff said. The program is here: [link]