Update: Valve's Doug Lombardi told Joystiq : "As a point of 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: Valve Time are reporting that the two-man operation Star Filled Studios have been bought by Valve, and will be heading up a new office based in San Francisco.
According to the LinkedIn profile of Star Filled's Tod Semple, a former programmer for PopCap, "my recent startup was acquired by Valve and we are opening a new office on the San Francisco peninsula."
Star Filled Studios is comprised of Tod, who has previously worked at Blizzard and LucasArts, and Jeff Gates, who did work on Maxis' Spore and Blizzard's Diablo 3. Both then worked together at PopCap.
Valve's plans for the company are still a mystery. While Star Filled Studios never announced what they were working on, their website states, "our games are made to be playable by everyone and available on iPhone, Steam and many different platforms."
The last company acquired by Valve was Turtle Rock Studios, who made Left 4 Dead before being rolled into Valve's Bellevue HQ. Turtle Rock have since reopened, now independent of Valve.
Thanks CVG .