Nah. It's all wrapped up nicely here. You don't want her to close the door, understandable, but this is it, sportfans. Game over.
Meh... name your loose end you wish she'd tied up. I think she tied up mostly everything. The only things still "open" are only open due to the nature of storytelling in general. By simply providing a descriptive world, some people will be more attracted to the filler material or "extra" bits than others. The world is so rich, I bet people could tell stories "inside" that world forever. For instance, I'd personally love to write a few short stories about all the hidden secrets in the Room of Requirement. I guess that's what fan fiction is for, though.
Considering Rowling dodged the FINAL BODY COUNT at the end of the book, I'm sure many fans are wondering what the final fate of many secondary characters were. But, Rowling has an appreciation for what bits are ultimately irrelevant (read her website for things/subplots she's totally cut out over the years). Fans could easily imagine "epilogues" for every single character in the story, like some crazy college comedy flick. Me, I think there's a limit to indulging the full depths of fan curiosity.
~ CB