Well, somebody blew up about fan fiction, and SF being a fairly small community, there's been a bit of discussion about it.
And it's been interesting to hear various people weigh in on the discussion. Predictable, I find the most interesting and cogent thoughts to be from writers of my generation, and who I've met.
Charlie Stross has a very well thought-out post on his attitude toward fan fiction using his characters or settings.
Nick Manatas presents a very interesting case of what copyright is and what it is not, using the rather complex case of HP Lovecraft as an example.
Me? I'm essentially still a fanfic writer, although I've gotten paid decently for one of them. And, as Silviamag said in the comments of Nick Mamatas' post, "I'll say it again: the day there's erotic lesbian fan fiction of my work is the day I've made the big leagues."