I realmly like the webmin system.
I wonder if a kind of system could be done that would be:
a daemon listens on a specific port (a port for configuration) on localhost.
An abstract layer handles a /etc/whateverfile.conf to "standard XML" translation (both sides).
The daemon handles the serving of thoses standard representation of configuration datas. And clients are available to format that XML into GUI, and command the daemon to write the modification into the corect file.
The idea is to separate tasks as in a client/server system.