Needed a place to put links for easy referral. Here they are. DISCLAIMER: I know nothing about the law. I’ve never read a Kenyon book, but read four Clare books years ago. NOTE: I’ve posted the following as a comment on The Passive Voice blog post, as well as my Tumblr (genrecats), and now here on my WordPress.
That “Clare did it first” thing is a fallacy. While it is true that Kenyon’s Chronicles of Nick were published AFTER The Mortal Instruments, Nick’s backstory is threaded throughout the Dark-Hunter series – which came out BEFORE The Mortal Instruments. This comment on a Dear Author post explains it: http://dearauthor.com/features/industry-news/wednesday-news-kenyon-v-clare-editions-at-play-star-trek-continues-and-disneys-so-meta/comment-page-1/#comment-808579
Here’s a photo of an early edition of City of Bones, which includes the word “Darkhunters”, before it was changed in later printings: https://twitter.com/has_bookpushers/status/698155918534537216
Here’s a Tumblr post with screenshots of Clare’s fanfiction compared with TV/film scripts: http://posh-brit-guys-are-hot.tumblr.com/post/138456381901/fuckyeahdiomedes-amooseintransition Not word-for-word copying, but lightly rewritten. That doesn’t relate to Kenyon, though; this is just Clare’s history.
Also, Clare tried to sell merchandise of her Lord of the Rings fanfic, but she may not have gained permission from the Tolkien Estate before she did: http://web.archive.org/web/20020526055402/http://verysecretdiaries.com/ Again, this is nothing to do with Kenyon – just Clare’s history.
I still don’t think writers unrelated to the case should worry about how the case affects them until the outcome. Kenyon isn’t trying to stop ANYONE and EVERYONE from writing specific things – just Clare. You only need to worry about “if this sets a precedent” when/if the time comes. The case is in early days yet – I’ve heard these suits can take years.