From everything I've heard, the ammo's legit. Not so sure the targets.
I'd be inclined to give credit to Hornady for capitalizing on the "zombie apocalypse" fantasy and maintaining a bit of humor coming up with this. I'd be hard pressed to believe that the bullets are any other than V-Maxes with yellow poly tips rather than red. The ammo probably works as well on coyotes as their other stuff does.
I'm just waiting for them to market hunting ammunition this way - you know, fancy commercials on TV, ads in magazines, ... Wait, they already do that, don't they? And people actually buy that stuff?