You are right, there is a total lack of originality in the genre at the moment. I am sick to death of zombies, vampires and quirky series set in small town America.
Er, there's exactly one
zombie show on tv these days. Two if you count Death Valley
on MTV which is barely on anybody's radar.
And there's only two vampire series: True Blood
and The Vampire Diaries.
(And, okay, Death Valley again.)
That doesn't seem terribly excessive to me.