I had two accounts of bleedthrough today, but can only remember one. I was walking down a hallway with a pipe going down it's length on the ceiling. Periodically it would split off into a room, one of these split off pipes was bright red for some reason, made me think I should go into that room. Weird that I have bleedthrough after only playing the Mirror's Edge demo. I'm pretty sure the second account of bleedthrough was related to Left 4 Dead, but I can't remember what it was for the life of me.