http://www.thesixthaxis.com/2014/08/...an-have-60fps/
The final game will run in 1080p with 30 frames per second on Xbox One, PlayStation 4 and PC, and will support up to 5760*1080p on PC for triple screen set-ups. Right now the team is focusing on providing an optimal experience for all players. You can unlock it in the file you’ve found, but it may affect the game’s performances.

Latest official update: we will offer the option to play with either 60 frames per second or 30 frames per second on PC at launch.