Seriously, what is behind this fascination with zombies?

Pop culture seems to be saturated with zombies. Zombie movies, zombie television shows, zombie books, more zombie books and even a report from the CDC on zombie preparedness. It is kind of old, but there is also a song about zombies! So what gives? Why the interest in zombies? Is it some reflection of our fear of death? Does it even go as deep as that? Why not a vampire or werewolf boom? What is the reason for the rise of zombies in pop culture?