/*Rowling*/ has called a news conference in London on Thursday to reveal details of "Pottermore," a mysterious website that has been taunting fans with the words "coming soon."
Theories include a Harry Potter encyclopedia, e-book versions of the novels or an Internet-based game.
Several British newspapers received what appeared to be a leaked marketing memo indicating the site is a Web-based game including a hunt for real magic wands.
It's not clear whether the memo is genuine.
Rowling's final Harry Potter novel, "Harry Potter and the Deathly Hallows," was published in 2007. Her publicist says "Pottermore" is not a new book.