I don't buy the notion that AI Wars is not really compatible with matchmaking systems. Yeah, it's great if you have a group of friends you know who all play, but for those of us who have to find teammates online, it's non-trivial. There's the subforum for it, the IRC channel, Hamachi, Steam... which only compounds the problem by fracturing the player pool into separate compartments. As for the objection about getting casual players that won't stick it out through a game, I don't think AI Wars attracts many people that would slog through the tutorial/solo games, find the forums, go to the trouble of joining a match and then bail: very much the exception instead of the rule is my guess.
A proper solution would probably be to build a lightweight matchmmaking system where you tell it what hours you're typically available to play, contact information, and game preferences, and it would email everybody when a good enough match was found and serve as an automated game organizer (preferably in-game, but on web would be just as good.) BUT, since I know that's not a high priority and would involve a fair amount of work, here's what I think is the best of my quick-fix alternatives.
Make a new subforum, or repurpose the existing one -- just a change in process. Right now it seems to be people posting with e.g. "Hi! I want to play! This is my Skype/email/whatever, I'm GMT-2" which I don't think translates frequently into actual games getting started. Instead, have the posts be info for a specific game startups, e.g.:
"I'll be running a game with all expansions, dual 8s, 60-star, Hard Spirecraft/[etc.], flexible on map type / AI types. We'll start [tonight/tomorrow/next Saturday/whatever] at 10pm GMT. Anyone who wants in please reply here, send email, or you can try just joining [IP] at 10. Expect the game to run 10-15 hours, we'll finish up next Fri/Sat night or two if we have to. Please don't join if you're not going to finish."
"WANT TO PLAY ASAP. STARTING GAME IN 3 HOURS. DONT CARE ABOUT SETTINGS PLZ JOIN WRITE BACK HERE"
Ideally, you could put a sticky with a simple template that people could fill out with the pertinent info.
Anyway, I'm just throwing that idea out there... it would work for me, but does that appeal to anyone else?
(For the record, the other quicky solutions that came to mind were tossing up a public google spreadsheet where you could list your info and see everyone else's, and... I'll be damned, I forgot the other one.