Gamasutra has an E3 chat with Valve's Doug Lombardi to clear up the status of Turtle Rock Studios, the developer acquired by Valve during development of Left 4 Dead. For a while the team operated out of Irvine, CA as "Valve South." This arrangement no longer exists, but Lombardi explains that this does not mean they actually closed the studio, as things were a little looser than that, and after L4D was complete, the remote office complicated the process of moving people onto different projects:

After several members of the Valve South team -- which Lombardi described as only ever numbering "nine or 11 in total" -- moved up to Bellevue, the remaining staff were not enough to justify a fully-fledged studio.

At that scale, "the idea of having an office with a receptionist and all of that kind of goes out the window," Lombardi said. As far as Booth and his current team, "that group of people looks like the original Turtle Rock again, and I think they may even prefer to call themselves that," he added.

No details were offered regarding that group's upcoming project, but Lombardi did conform it is once again a collaboration with Valve.