CW already has a vampire show though, one with a somewhat popular following, along of course with "Supernatural" in it's final season and the upcoming "The Secret Circle".
They're already remaking a "Buffy" film which has caused the ire and wrath of many Buffy and Joss Whedon fans. Creating a rip off (that is essentially what you're talking about Temis you've just worded it carefully) would incite even more fans. LOL. One of the reasons why Buffy was a successful show was because of her creator and the people that he put in place to write her adventures. It wasn't just executing a "formula".