Well, only two multiplayer games, but they are games. One is zero-G astronaut battler (with excellent space furniture), Shattered Horizon, and the other is slightly wonky Wild West shoot 'em up Lead & Gold: Gangs Of The Wild West. They're temporarily free to play on Steam over the weekend, with a large discount for actual permanent purchase if the freeness persuades you of long-term appeal.
Hmm. That - Shattered Horizon, I mean - would have made a good game club outing. As Phill pointed out, it's benefited great from its updates. Oh well, maybe we squeeze in some astronaut deathmatchery between the Arma II exploits. Hell, I bet Notch goes and makes SMP work properly before the weekend and then I will have to play that too.