As part of Pottermores Trick or Treat Celebration leading up to Halloween, it has been revealed that on October 31 J.K. Rowling will release a new 1,700-word story!
The story, which was teased by Pottermore in this post last Saturday, will feature none other than Dolores Umbridge. From Pottermore:
"Umbridge is not only one of the most malicious Potter characters, [but] she is [also] the only person other than Lord Voldemort to leave a permanent physical scar on Harry. The new exclusive J.K. Rowling content provides a rich, 1,700-word back story about Umbridges life filled with many new details, as well as Rowlings revealing first-person thoughts and reflections about the character."
http://www.mugglenet.com/2014/10/j-k-rowling-to-release-new-story-on-halloween/