inFamous 2’s Vampire DLC Still Makes No Sense, But It’s Got Some Nice Art!

I've no clue why Sucker Punch has decided to produce this bit of vampire-related DLC for inFamous 2, unless they're aiming for a Holloween release date. Still, even if they were, why Vampires? What do Vampires have to do with Conduits, genetically mutated human-beasts, and stark analogues of New Orleans? Other than "Interview with a Vampire", I mean.