When looking throught the new gameplay video, there was one thing that stood out to me (See the image at http://images1.wikia.nocookie.net/dishonoredvideogame/images/c/c1/Untitled5.png). I have seen the graffitti'd symbol before in this game, but seeing it here makes me thing of the Lamba caches from Half-Life? Do these have a similar purpose? Or are these the red Xs that mark the buildings of Weepers?

Those are the red Xs that mark weeper buildings. I'll be placing a screenshot in the appropriate section of the wiki, soon, to stem any such theories.

Oh, okay. Nevermind my conspiracy theory!