1. I am having massive dental pain on the side of my mouth *not* currently scheduled for major invasive dental surgery. WHY GOD WHY?!?
2. I thought that this debate would be over by now, but since it's not, allow me to weigh in on Helen's awesome
Take Clothes Off as Directed. Go read it if you still haven't: on top of being a wonderful story in its own right, it does a good job of taking Xanthe's AU -- which by the author's own admission, wasn't particularly interested in social realism -- and grounding it in the mundane, and by doing so, reinventing it completely.
Some people have suggested that the "unauthorized homage" was mean, or unwarranted, or otherwise inappropriate. But, if anything, I see it as a tremendous tribute. You don't write a story that long, that intricate and emotionally resonant, just to flip someone the bird. You do it because someone else's idea has gotten into your bones, into your brain, into the innards of your being.
It's the sort of success that every writer should hope for. That it goes places that the original writer never could have expected shouldn't come as a particularly huge surprise to a fanfiction community that has also encompassed gay penguins, mail-order brides, and unicorns.