Australian Classification Board has a rating for something called Warhammer 40K: Kill Team (via Joystiq). This previously unheard of title is being developed by THQ Digital Studios UK, who were responsible for Red Faction Battlegrounds. We should probably expect a digital-only, smaller title instead of a full-on sequel to the upcoming Warhammer 40K: Space Marine, then.
One description of a Warhammer kill-team reads: “a small group of Space Marines, usually no less than five Astartes but no more than a reinforced squad in size, that are tasked with carrying out a specific objective, such as the destruction of a particularly dangerous or strategically important individual, hence the name.”
Sounds like a good setup for a co-op game of some sort. The Classification Board rated the game “M”; we’ll rate it as “promising” for now.