JKR: No, I see that, and yeah, I follow your line there. I can't — I mean, obviously, there are lines of speculation I don't want to shut down. Generally speaking, I shut down those lines of speculation that are plain unprofitable. Even with the shippers. God bless them, but they had a lot of fun with it. It's when people get really off the wall — it's when people devote hours of their time to proving that Snape is a vampire that I feel it's time to step in, because there's really nothing in the canon that supports that.
Here is the entirety of the second part of this interview.