The story line was OK, and I like that it tried to infuse some “plausible” (though I use that word lightly) explanation for why vampires and ware-wolves are the way they are. There was nothing particularly good or bad about the story, but it did keep me interested.
But the real good thing about this movie was Kate Beckinsale. The whole movie I kept getting distracted from the plot, dialog, etc. by how amazingly beautiful she was. I have to say she is my perfect woman in this film. :-) If you see it for no other reason, see it for her—she carried this entire film.