Last month we mentioned a rumor that director David Yates had been asked to return to the Harry Potter franchise.
A new rumor has now surfaced online stating that American director Michael Hoffman will be directing Harry Potter and the Half-Blood Prince. Mr. Hoffman has directed Soapdish, One Fine Day and A Midsummer Night's Dream.
An announcement will be made by Christmas, so for now, all we can do is treat this new information as a rumor and wait to hear the official news.
UPDATE: Both of these rumors have been debunked by Warner Bros.