The Leaky Cauldron is reporting that two different spokespeople for JK Rowling are calling into question recent rumors that a publication date for Harry Potter and the Half-Blood Prince would be announced in January by bookstores. In fact, the only place that the news would appear first would be on JK Rowling's web site.
According to the spokespeople:
If there was an announcement about to be made early next year no one would know about it. When there's news it will be on JKR's site.
Recent rumors claimed that some bookstores around the world have been receiving memos suggesting that a publication date was imminent and to be prepared for questions from customers. At this time we can only suggest that you checkout out Rowling's site on a regular basis for any announcement dealing with the book.
HalfBloodPrince.info will also send out an alert when the book is officially announced.