J.K. Rowling recently updated her website to let people know that there are currently no plans to release an enccyclopedia in book form, and that for the time being all new Potter information will appear on Pottermore.
Updated May 2012
I have been enjoying sharing information about Harry's world on Pottermore for free, and don’t have any firm plans to publish it in book form.
This update comes in stark contrast to her previous statement that was released when Rowling announced The Casual Vacancy and relaunched her site back in April.
For a long time I have been promising an encyclopaedia of Harry's world, and I have started work on this now – some of it forms the new content in Pottermore. It is likely to be a time-consuming job, but when finished I shall donate all royalties to charity..
The above statement has since been removed from her site.
05-22-2012 at 12:00 AM