I just read Abraham Lincoln: Vampire Hunter (yes, I was embarrassed to buy it at the airport) and it was quite entertaining except for one point: it continued the ongoing weakening of the vampire mythos.
Everyone knows that vampires are powerful and can defeat almost any human one-on-one, but what makes vampires interesting are their vulnerabilities. The only logical reason that vampires don't take over the world is that they have to sleep during the day and die almost instantly in sunlight. Even as recently as even 10 years ago (see: Buffy the Vampire Slayer) the literature held to this simple formula. Because of this huge weakness vampires must depend on secrecy to protect themselves from humans. In Interview with the Vampire (Vampire Chronicles) Louis destroys the entire Paris coven by burning their theater down around them just as the sun is coming up.
Without extreme vulnerability to sunlight we get inane garbage like Twilight wherein vampires sparkle in the sun and have little reason to hide their existence from humanity. It's dumb.
Other vampire weaknesses (e.g., crosses, garlic, holy water) can fall by the wayside because they aren't really critical to the mechanics of the mythology. It's sunlight that keeps humanity alive, and no vampire story should forget it.
