Just a head's up, Stardock will soon be putting into beta a new Object Desktop program called SoundPackager (or some name that isn't already trademarked <g>). 

It will do for system sounds what IconPackager did for icons.  It will add a host of new sounds for all kinds of events on the system that will help spruce up your environment and give you greater control over it.  We will have a WinCustomize section for users to submit their sound packages as well.