It appears Wikipedia had some answers:
In an interview, author J. K. Rowling gave additional information about the characters that is not mentioned in the book. The epilogue does not directly state that Ron and Hermione are married, but Rowling confirmed that indeed they are.
- Harry and Ron are both Aurors; Harry is the department head, and Hermione is "very high up" in the Department of Magical Law Enforcement.
- Luna Lovegood has become a naturalist of sorts, searching the world for odd and unique creatures.
- At Hogwarts there is a permanent Defence Against the Dark Arts teacher and the jinx Voldemort had placed on this job was broken after his death. There is also an unknown headmaster, as Professor McGonagall, who was the interim Headmistress, was getting too old to assume the position permanently. Rowling did not identify either the Headmaster or the Defense against the Dark Arts teacher.
Rowling felt that including all of this information in the book made it too "neat" of an ending.
Oh, well, I see her point, but still...