Vampires require a unique face and sun damage.
Werewolves require animations, claws, and skin.
Overall id say Werewolves are a little more difficult than Vampires, but I wouldn't say they're light-years away.
@JDH, im not a fan of Zombie mode for World at War and Black Ops, but they are slowely becoming more popular than Treyarch's COD games themselves...Be careful what you wish for, but most of the time you'll actually be satisfied with being given what your asked for.