But we already know there's something left. This is only the second year at Hogworts. The third book is already out in the UK, and is selling like hot chocolate in the Alps. And thereby hangs a tale. Amazon UK has shipped a significant number of books to US addresses.
Territorial rights are anticompetitive and bad for both writers and readers.
Rowling's writing is very, very clean. The reading level stays pretty low without being obtrusive about it. She is writing a series without seriesitis. Each book really does stand alone, but the repeated business and background are done naturally. There are a lot of experienced authors of Interminable Fantasy Series who could learn much from J.K. Rowling, who wrote the first half of the first book on the kitchen table in a shelter in Scotland.