Having a 'demo' mode play as a screen saver with some music might be nice... I wouldn't see the point in being able to play it though while it's a screen saver... If you want that, just launch the program.
True, but a dynamic screensaver where you can say, put a few songs the program file's folder, and it would play those tracks while going through a PC controlled demo mode would be an awesome screensaver.
Maybe one where they show highscores from the currently played / most played songs as well?