Sega said at GamesCom yesterday that Rebellion's Aliens Vs Predator will have a good variety of multiplayer modes and make decent use of Steam's feature-set.
All three formats - PC, PS3, 360 - will have 18-way multiplayer, we were told after a demo, and all will fgeature mixed and pure-species game modes.
"If you're playing on PC, we're also leveraging Valve Steamworks to provide anti-cheat matchmaking Achievements, and we're using Steam Cloud as well, so your saved games and settings" can carry over onto any PC you happen to be using, Sega chap Rob Bartholemew said.
Four-player co-op will be present in a Survival mode, where you and friends play as marines facing waves of aliens. Sounds a bit like Gears 2's Horde mode.
It all looked very good from where we were sitting. Very bloody. Screamy, even. It's out early next year.