You know, I just finished re-reading Pride and Prejudice, and I keep seeing all these P&P sequels on the shelf at the bookstore, and I keep thinking to myself, "why?"
I suppose there are a good many Austenites who would ask the same of Harry Potter fanfic, but that strikes me as a horse of a slightly different color, somehow.
Ooh! Time-travel fic, shipping Percy Weasley and Mary Bennett! I hate myself now.
ETA: A Wizard for Mary by jedibuttercup. Harry Potter fandom: fear it!