Your music can remain where it is - you just point the new SS installs at the UNC paths to your existing music collection.
That actually would be a good idea.

But it really takes away from the centralized server concept. I have all my configs on my server. In addition, you would have to log in to each server separately to control them. Updating/modifying your server would become a pain. I also don't want to have a full-blown subsonic server running on all of my machines.
I think that management would become increasingly difficult as your music collection grows and the number of custom modifications to the server increases.
Imagine going on your laptop, selecting the right player from the scroll-down, and being able to control the other computers using that player!
This
http://forum.subsonic.org/forum/viewtopic.php?f=3&t=8552 seems to be more or less what I am talking about.
With the correct permissions, having each player synchronize with the other instances of that player. Music would then play across all computers participating in that collective streaming. When the user clicks "Stop," all the other instances would receive the stop signal and stop as well.