Update - Doug Lombardi of Valve confirmed that Semple and Gates have been hired, but offered a clarification: "This is probably better categorized as Valve hiring two new employees instead of an acquisition of a company or opening of a Valve SF office."
Original Story - An indie start-up composed of former PopCap developers has been acquired by Valve. The developer Star Filled Studios was just composed of two men: Jeff Gates and Tod Semple, both of whom formerly worked at PopCap. Semple says they're opening a new office in San Francisco.
Valve co-founder Gabe Newell confirmed the acquisition, telling Edge: "The guys who did PvZ, down in the Bay Area, we're helping them set up a Valve subsidiary there."
The studio site also references work on high-profile titles at Maxis, LucasArts, and Blizzard. The two were working at PopCap's San Carlos office until they were made redundant in August by the company layoffs. They went on to form SFS in September.
Valve's last acquisition was in 2008, when it took on Turtle Rock Studios. That led to the company getting behind Left 4 Dead and then closing the studio before it reopened as independent in 2009. Valve didn't give word on what Star Filled Studios will be working on.