I downloaded and tried NetRemote from Girder. It looks like it could do a reasonably good job of providing client/server like capabilities with MC. However, it doesn't work from my media server. I have been back and forth with their tech support numeorous times, and they are very cooperative, but something is interfering with the communication from the client to the server. All other connections (including MC web interface work fine!). However, if it did work, it would seem to give a user access to the server, create and maintain playlists, etc.
This type of functionality would be great from MC. If this is ever to be considered, I would also ask that certain controls be available over the client. If the wife and kids are to use it for maintaining their playlists, I would want to constrain them within certain areas, and not let them reconfigure some of the settings on the server.