New J.K. Rowling Children's Book!

J.K. Rowling is one of the biggest Children's authors, so when we heard that she is writing a new series for Children, we were amazed. On Radio 2 she commented "I have an idea for a children's book, actually I have written part of a children's book that I really love, so I'm definitely going to finish that. There will be another children's book."

We know nothing else about the new book, but with Rowling's busy lifestyle and numerous books being adapted for TV shows/musicals/etc we know it won't be hitting our shelves any time soon. What do you think her new book will be about? Something fantastical like Harry Potter, or a contemporary like her adult books?