Of course, Tolkien's unpublished epilogue DID have that delicious tidbit about Frodo being Sam's "treasure" and how that was so obvious that even a teenaged Elanor knew about it, thereby enabling all F/S devotees to say that they have canonical backup, damnit!! I got a lot of mileage out of that myself, back in the day.

I thought they were all going to go off and be on a sitcom

I wouldn't be the least bit surprised if Rowling takes a few years' vacation and then starts writing about Harry's kids. Or licenses out the junior Potters and Weaseleys for fiction or films or graphic novels or whatever. I mean, why settle for just being a billionaire?

One question -- does she do anything with Aunt Petunia? A few books back it seemed like she was being set up for something important.