It's all over the internet. J.K. Rowling is departing from Harry Potter and writing her first "adult" (as in non-young adult) novel. There aren't any details on the new book (as typical with Rowling announcements), but it is worth mentioning that this is not the first time she has announced a new book in recent memory.
In 2006 she announced a "political fairy tale" which still has yet to reach publication. In 2007 she announced she was writing another two books in addition to a HP encyclopedia (none of which have been released). In 2008 she announced she was nearing completion on her "fairy tale" and writing again in cafes (still nothing though). Finally we can all recall the Pottermore debacle which was a lot of hype all for naught as the company struggled with management issues and minimal new information on the HP universe.
This is not me being critical of Rowling mind you, just skeptical that a new book is truly on the way. Better to protect your and my feelings with facts instead of blind hope that this will finally be the year she releases something.