Interesting remarks about the story and characters as that seems like one of the biggest unknown factors at the moment.
Yup, the only thing we know about the story is that it's based on the prophesies of a Doctor (and I can't for the life of me remember his name!) who was an advisor to one of the Kings of England in the 1800s. Makes the story a great deal cooler when it's based on real prophesies made by real people in history imo. It was mentioned by Gabrielle in an interview around E3 I think.