Amnesia: A Machine for Pigs is an indirect sequel to the horror game Amnesia: The Dark Descent (http://amnesiagame.com
As described in the joystiq article (http://www.joystiq.com/2012/02/22/amnesia-a-machine-for-pigs/
"It's not a direct sequel, in terms of it doesn't follow on from the story of Amnesia. It doesn't involve the same characters," Dear Esther writer Dan Pinchbeck told me. Instead, Amnesia: A Machine for Pigs will be set in the same "alternate history and set in the same universe.
AAMFP is a collaborative effort between Frictional Games and thechineseroom. Coming fall 2012.