And on the basis of knowing what you're getting into, since the trailer either said or at least strongly implied that the kick-ass people were genetically modified soldiers, i feel i should clarify that according to the movie itself the US Government was trying to develop a kick-ass soldier treatment from a newly discovered disease, but they screwed it up and the resulting virus escaped and started turning people into vampires. So kick-ass powers, need to consume blood in some fashion, there's some kind of terminal condition attached, and they're accidentally infected "victims," not purposefully created soldiers. I spent the first five minutes of the film busy readjusting my expected paradigm =P
Oh, and it took Gun-kata to a whole new level by adding retractable swords to the handles of submachine guns :)