Have you considered leveraging the RSS Wallpaper functionality of Windows 7, documented at http://msdn.microsoft.com/en-us/library/bb773190(VS.85).aspx#slideshow_settings? You can publish a theme (or maybe set of themes by resolution) that sets the wallpaper to an RSS feed of your latest wallpapers.

I bet there are some guys that don't like reading random stuff in the db tweet eh, lol.