On GameInfoWire. Not much to go on there, but there’s a little bit on multiplayer:
Aliens: Colonial Marines will feature a story driven single-player mode and an all-new four player co-op mode allowing players to share the chilling experience with three friends. In co-op mode, each player will assume the persona of a Colonial Marine and have a distinct role to play in the completion of every mission. Additionally, more multiplayer modes will be revealed later in the year that will complete the Aliens video game experience.
More through the link. The Gearbox-developed shooter’s out on PC, 360 and PS3 in the fourth quarter.