I know this is an old topic, but I would like this functionality as well... I would like to be able to run a server on my local network on a machine other than the one I play on. I have a small dedicated Linux box I could use for such a thing, but it doesn't run a GUI, and the main machine I use is a laptop (so it goes offline whenever I close it).

I think just having the option there to "add custom server" wouldn't drive too many people away from the official one, as long as the official server is the only one there by default. Like how Firefox Sync allows you to specify another server but I don't know anyone that does it personally... only the people who want/need that functionality would use it. :P