After thinking about de-nuctifying the world I've started to investigate creating a Pidgin (formerly Gaim) plugin to control Skype. This means you're still using a closed network, but from an open program, which makes migrating easier (and allows people to try multiple networks from the same interface).
The Skype API docs are pretty good and it looks like the API can support at least controlling status, sending and receiving text messages, and making and receiving phone calls. So in principle a Skype plugin for Pidgin is a possibility.