Not only said duel, but the last 150 pages were fantastic.
Do you know that Rowling is planning to write an Encyclopedia of every character in the Harry Potter series? Including notes on such things as the epilogue?
Oh, and it might satiate the curiosity of some to know that harry is head of the Auror department, Ron is also an Auror, and Hermione is working her way up through the Department of Magical Law Enforcement, I think it is.
She also has two projects she's going to work on once she's done taking a break with her family. One for kids and one for adults. That's all I know about that.
It sounds like she won't be doing anything further with the Harry Potter series asside from side books like the magical creatures book. She didn't say she'd "never" do anymore Harry Potter books, but it sounds as though she won't be doing anymore.