Swift also ended up helping out on the Left 4 Dead series.
All we have to go on about Swift's new project at Airtight Games is this snippet from Square Enix:
"PAX attendees will be the first to see Square Enix and Airtight Games globally reveal a top–secret joint project through their exclusive panel. Meet the development team, including Creative Director Kim Swift (Portal, Left 4 Dead 1, Left 4 Dead 2) and the rest of the Airtight Games team, and hear their explanation of how they are bringing an incredibly fascinating and quirky game to life."
If you're at PAX, you can attend the panel on Saturday at 7:00 pm in the Pegasus Room.
Eyebrows were raised over Swift's departure, especially so since she left not long prior to Airtight Games released its first project, the poorly received Dark Void.