I've always assumed it was supposed to do something but never cared enough about it until now...  I've tried it on DS2.0, 2.5 and 3.0beta, tried it on different machines with different OSs (XP, Vista and 7) - the only common factor between these machines that I can tell is that they all use nVidia gfx cards of one sort or another (GeForce 3, 6600, 9300 and 9600).

I've only ever gotten the static blue background.  It's not a particularly ugly static blue background though

So I've just noticed that the preview window in 3.0beta actually shows the Watercolour Dream properly.  It's the first time I've seen it in motion.  I'd like t try and get it in motion as my desktop picture now, too Any suggestions?