Via The Telegraph.

"Writing under the pseudonym Robert Galbraith, the Harry Potter creator wrote a 450-page crime novel called The Cuckoo’s Calling. ...

... When approached this weekend, Miss Rowling said: “I had hoped to keep this secret a little longer because being Robert Galbraith has been such a liberating experience. It has been wonderful to publish without hype or expectation and pure pleasure to get feedback under a different name.”

Interesting. Very interesting. I wonder if she wrote it under a pseudonym because The Casual Vacancy was so poorly received by most.