Rowling's Reported Mystery? It's Been Solved.

The only topic getting more media coverage than Oprah's next book club pick is what J.K. Rowling is up to now that the Potter series is done. Speculation reached its zenith during the Edinburgh book festival, when Scottish crime writer Ian Rankin reported that his wife, Miranda, had seen Rowling "scribbling away" in an Edinburgh café, supposedly hard at work on a detective novel set in the Scottish capital. This anecdote was immediately reported that night in an early edition of The Sunday Times, after which it was picked up by The Associated Press and spread like celebrity sex tape footage through the rest of the world. The only problem? Rankin was kidding. According to the Guardian UK, Rankin has confessed, "This is a joke that got out of hand."
Whoops. Nice fact-checking, folks.
So what is Rowling up to?
Your guess is as good as ours (and The Times' and The Associated Press').