This is a video describing "Soul King," one of the new multiplayer offerings in F.E.A.R. 3. Later this year, you'll move about as a spirit, possessing the bodies of people and using their weapons to kill other people. The video covers it pretty well.
What I find fascinating about this mode is that it's pretty much the gameplay found in Geist, a Nintendo-published game released in 2005. In that, you were a spirit and could move from body to body, using the skills and equipment of each body to fight people. In multiplayer, that meant hopping bodies to take down other spirits. Soul King has taken the same gameplay, switched up the scoring a little and added a "King of the Hill" mechanic.
Here's the bit that amuses me: The early working title for Geist was "Fear," changed at some point about a year before Monolith first announced F.E.A.R. at E3 in 2004. F.E.A.R. went on to sell a ton of copies, spawning expansions and sequels. Geist wound up largely forgotten, its core gameplay mechanic now a multiplayer mode inside a game which bears its former name.
It's a funny old world.