The upcoming Heroes of Shadow supplement for fourth edition will feature vampires as a character class. Vampires as a character class. Vampires. As a character class. As a D&D Essentials style character class.
This is an idea I hope they explore further. It seems to me that racial classes done in a D&D Essentials style could be pretty interesting. It seems like a good way to do monstrous characters anyway. I think I just might homebrew my very own dragonborn class.