According to the 40K wiki, a kill-team is "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."
The title's being developed by THQ Digital Studios UK, the same house behind Red Faction: Battlegrounds, which leads us to believe we're talking about some sort of downloadable title. We were about to say it also leads us to believe it won't be very good, but who knows? Maybe the studio was working so hard on Kill Team that it forgot to make Battlegrounds good? Today is a holiday after all, the least we can do is to be generous.