Amnesia: The Dark Descent and its sequel Amnesia: A Machine for Pigs, is already teasing its next project. The above image is the result of visiting nextfrictionalgame.com, a placeholder site the studio has used to tease previous projects.
The progress bar above seems to be increasing as more individuals visit the site or as time goes on. Presumably, once it reaches 100%, more information will be presented.
Frictional Games shipped Amnesia: A Machine for Pigs earlier this month. In our review, we said the game is "punctuated by moments of disquieting and hideous awe," though we felt it ultimately wasn't able to reach the high bar set by its predecessor.