Rowling/Couric Interview
Dateline NBC has the interview transcript of the interview that Couric gave. Below is a small bit, but check out the full thing HERE.

J.K. Rowling: Harry has, I think, taken the view that they are now at war. He does become more battled hardened. He’s now ready to go out fighting. And he’s after revenge.
Couric: If you, God forbid, got hit by a bus...
Rowling: Yeah, it's perfectly possible, I'm a very distracted person.
Couric: Does anybody know your ideas for book seven?
Rowling: No.
Couric: Nobody? Not a soul?
Rowling: No.
Couric: Not Neil?
Rowling: I wouldn't tell- Neil would forget. You know, he wouldn't be a good person to tell anyway. No, no one knows. Which is good, because if I do get hit by a bus, I would really hate to think someone else was going to take over. It's my baby.
And as she looks forward to a literary life beyond Harry Potter, Jo says she will savor her final journey aboard the Hogwarts Express.
Couric: When you finish it, and obviously you have a lot of work ahead of you, are you going to be sad or-
Rowling: Yeah. It's going to be really emotional to say goodbye. I'm going to find it very difficult. But it must be done, it must be done. It's been a fabulous ride, but you have to know when to get off, and I know when to get off, and it will be the end of book seven.
Couric: Terrifying, though, to think about what you'll do next-
Rowling: No, liberating. Definitely. Yeah. It is. The world is my oyster. I can do whatever I like.