Found this on the online Telegraph

Title of sixth Harry Potter book revealed
(Filed: 30/06/2004)


The title of the latest instalment of the hugely popular Harry Potter series has been unveiled.

Harry Potter and the Half Blood Prince, will be the sixth in the multi-million-selling tales of the schoolboy wizard.

   
A scene from the latest film Harry Potter and the Prisoner of Azkaban
Author JK Rowling revealed the title on her official website just as hoaxers tried to fool fans into believing the new book would be called Harry Potter and the Pillar of Storge.

Miss Rowling said that she had been using the title "for ages and ages". And she also gave fans a teasing hint: "The Half Blood Prince is neither Harry nor Voldemort. And that's all I'm saying on that subject until the book's published."

Lucy Holden of Rowling's publishers Bloomsbury said "We don't want to spoil the title but it has been hinted at on JK Rowling's website and we can now confirm the title will be Harry Potter and the Half Blood Prince."

Whatever the name of the book, it is set to induce near-hysteria among the huge ranks of Potter fans. The fifth book, Harry Potter and the Order of the Phoenix sold 1.77 million copies on its first day last year. It sold almost five times as much as the first day sales for the fourth in the saga, Harry Potter and the Goblet Of Fire, which was itself the fastest-selling book in history on its first weekend of publication in July 2000.