All though it was thought that Pottermore would be J.K. Rowling’s unique Encyclopedia, it turns out that she is taking her time, and working on an Encyclopedia of the Harry Potter series.
It was confirmed on a FAQ page in her new website.
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.
This is the first time that she has said she is working on an Encyclopedia… she has said that she will consider making an Encyclopedia before.