No, there's not an eighth Harry Potter book coming out. There is, however, good news for Potter fans who can't make it out to London.
The script for the London production of Harry Potter and the Cursed Child will be published in print and as an eBook. The play, which debuts this summer in London's West End, is written by Jack Thorne and is based upon a story by Thorne, J.K. Rowling, and John Tiffany.
The print edition publication (by Scholastic in the U.S.) and eBook release (by Pottermore) will coincide with the play's premiere on July 30. The eBook, launching at midnight, will cost $14.99, or a little more than half of a galleon.
The play's action takes place 19 years after the final book leaves off. Potter is now father to three children and an employee of the Ministry of Magic. So, yes, it's a new story, but not an official book that J.K. Rowling has spent years crafting.
And a warning: Because the play will still be making tweaks to the script when the Special Rehearsal Edition is published, the eBook may have content that differs from what ends up appearing on stage. In other words, don't rule out that trip to London just yet.