One of the things that's always a challenge in superhero games is giving the character new powers as they go. Infamous 2 got to bypass Cole McGrath's origin story, and as a result introduced new powers while presenting a faster-moving, more enjoyable story than the first game.
That said, it's always a good thing to get more powers, especially if they're vampire powers. The launch trailer for the new standalone add-on content Infamous: Festival of Blood shows a new sort of origin story, as Cole McGrath is bitten by a vampire and sets out to win back his free will from some apparent vampire dominatrix master person named "Bloody Mary." Geddit? Because blood.
I've only just gotten this downloaded to my PS3, so I haven't played yet. But really, they had me at "electrically charged vampire superdemon."