They will die out. They won't be completely gone but we won't be obsessed with them anymore. We'll have a new obsession soon enough. Honestly I'll be glad when it's over. I don't hate zombies but they've gotten kind of boring. And I'm getting tired of them shoved into every video game. I mean my favorite game Skyrim (One of the many examples of games with zombies where they don't fit) has zombies. They renamed them Draugr (I think that's how you spell it) and gave them a makeover to make them fit into the world of Skyrim but you don't need to be a rocket scientist to tell what they are.
Just like with all other fads this one will disappear soon enough. I think people are sick of vampires by now and I see zombies in the same way. The zombie apocalypse jokes are getting old and I would guess within a year or so the shows will be done and we will move past it.
Yes, there must be a breaking point for all of these zombie films and movies. With so many other monsters getting short shrift, surely Americans will begin to tire of the living/walking/whatever dead. Is there really such demand for literary classics and historical figures killing zombies? I think the novelty will wear off soon.
There is a long-standing theory that zombies are popular during times of economic depression and vampires are popular during times of economic boon. In today's difficult times, it is easy to see why people are attracted to the idea of the everyman hero who survives the zombie apocalypse and defies all odds to defend his family and those he loves against the living dead. With shows like The Walking Dead continuing to gain in popularity, it seems unlikely that zombies will fade from the mainstream any time soon.
Zombie love will never die. From the Evil Dead to The Walking Dead, there are too many parallels with current culture for America's love of zombies to ever go away. Artistic creators still can use the zombie motif to tell their stories, plus the makeup and kills are always pretty cool!