since you asked...
My opinion is this:
Its great to have a ton of random people on a hamachi server.
None of them talk to each other. Guys a, b, e, f, y, and z can all be playing AI war, and might even want to play a multiplayer game together. Unfortunately, short of chatting to every single other guy on the list 'hey wanna play?' even ctrl v'ing it to everyone might take a while.
no, hamachi is not the answer.
What we require, and Ive probably mentioned it somewhere else, is a unified chat server that /anyone/ playing AI war has access to. While your game is open, your connected to the chat (naturally, on/off buttons, ignore buttons, yada yada.) There needs to be a way so that people playing games can talk to each other. IRC is great and all, but still requires people to have another program open just to run IRC..
From how I understand it, IRC shouldnt be that hard to put into a game, so.. Make an IRC channel of some sort (hell, use the rtsnet one) and put an irc-ish client into AI war.