Update: CI Games has formally announced Lords of the Fallen in a press release. There's little new information about the game besides a new piece of art and some story blurb. It will be at E3.
"Set in a richly created fantasy world where the Gods have failed mankind, players will take on the role of a human named Harkyn who sets out on a quest to stand against an apparently unstoppable supernatural force. Players travel across a world that is deeply dived by those that follow and others that resist the Fallen God. Along their journey they will be faced with a series of decisions that will alter both the world and their character thus dramatically impacting the storyline."
Original story: Lords of the Fallen will be "a challenging game" - an RPG a bit like Dark Souls but for PC, PlayStation 4 and the next Xbox.