The appeals court has ruled on Klinger's lawsuit against the Conan Doyle Estate. The characters of Holmes, Watson, etc are public domain as long as they are based only on the first 50 stories. The last 10 stories remain in copyright, and are considered "derivative works" of the original, earlier stories. So you only need to pay a license fee if you use material featured only in the last 10 stories. (If you read the PDF, the judge makes interesting arguments based on Shakespeare's characters changing in different plays, and well as the Star Wars movies being chronologically out of order.) Now we'll just have to see if the Conan Doyle Estate is stubborn enough to appeal the ruling yet again.
In the meantime, I finally broke my writer's block on Far From Over. I keep trying to login to Fanfiction.net to add the new chapter, but I can't get in. You can read it on AO3. I guess I'll keep working on the next chapter.