American Gods was designed to be if not open-ended, at least a trilogy kind of shape, so there's definitely one more book, probably another couple of books there to get written.
Neil GaimanBirds are the last of the dinosaurs. Tiny velociraptors with wings. Devouring defenseless wiggly things and, and nuts, and fish, and, and other birds. They get the early worms. And have you ever watched a chicken eat? They may look innocent, but birds are, well, they're vicious.
Neil Gaiman