I ran across this transcript of a web chat JKR did recently... she answers a lot of questions about the final book. (Unfortunately one question that was not asked, or was ignored, was "why on earth did you leave in that dopey epilogue you wrote years ago instead of giving us something more interesting?') But she does discuss what all the main characters do after the book ends, which was definitely something I was wondering about. It's too long to cut & paste, so here is the link: