There is a great interview with King on The Book Beast here.
Here is a quote describing the basic premise from the intro to that interview:
Tomorrow, Stephen King and Scott Snyder will turn loose American Vampire, a new DC Comics series about a Wild West outlaw who’s a sociopath even before he gets vamped. This fresh, rough-and-tumble breed of vampire will rip out throats and hearts, but they most assuredly won’t sparkle—sorry Twilight fans.I have paired this post with my report yesterday on Joe Hill's new book. Either is a great reading option for fans of some good old fashioned story telling (if you don't mind some chills and a bit of blood). But my question is: Is Stephen King's DNA taking over the world? And if so, why does it not feel like such a bad thing?