J.K. Rowling has raised the dangerous possibility of writing new Harry Potter book.  In a taped interview with Oprah Winfrey [via The AP], Rowling said the characters are in her head and "could definitely" write several new books about them.  Rowling added:

"I'm not going to say I won't. I don't think I will ... I feel I am done, but you never know."

While it's wise to never say never, I hope Rowling recognizes that she stuck the landing with Harry Potter and the Deathly Hallows and should leave well enough alone.  But you never know when Rowling might need to earn enough cash to buy an industrialized nation.

To date, more than 400 million copies of the Harry Potter books have been sold.