Executive Meddling: Dead Beat's necromancers were originally scheduled to turn up in book 8, with Proven Guilty as the 7th entry in the series. Mr. Butcher swapped them around when his publishers insisted that the seventh Dresden tale, being the first hardbound release, really ought to feature something "truly spectacular". Cue the zombie dinosaur.
One of Us: At Dragon Con 2014, Mr. Butcher said when he wanted to look up some information about his own series he will look at the Dresden Wikia and TV Tropes. He compliments the tropers attention to the minute details, including the Shout-Out pages. See video here.
The Other Darrin: In the audiobooks. Books 1-12 are narrated by James Marsters. Unfortunately, Marsters was unavailable for Ghost Story, which was narrated by John Glover. Fan reaction to the change has, thus far, been... mixed.
Alternatively, the switch could be Justifed in a meta sense: Given that for almost all of Ghost Story, Harry was dead, and therefore in a markedly different state and there are even suggestions that he wasn't even Harry proper, just a shade (though that was wrong), having a new voice for that book adds to the ambiance of 'somethings wrong'. Narration returns to James Marsters when Harry comes back to life
Marsters returns forCold Days, possibly due to fan backlash. Furthermore, a rerelease of the Ghost Story audiobook, with Marsters narrating it, was released on April 21, 2015.
Nordling: It reminds me, do you like torturing your characters? Is it more fun to torture them a bit? Jim Butcher: I don't like torturing my characters, I like torturing my readers. It happens to be that torturing the characters is the best way to do that. Abstruse: You and Joss Whedon are going to put me in my grave. Jim Butcher: That's the idea. I want you to lose sleep and miss work and all kinds of thing.
Due to readers' frustration with the wait between books, Jim Butcher and his editor at Penguin Random House are taking inspiration from one of their favorite film trilogies and declaring a temporary hiatus on publication of the Dresden Files novels. "I think Peter Jackson had the right idea with the Lord of the Rings movies," Butcher explained. "The trilogy took eight years to make. You can't expect an audience to wait that long between installments. It made more sense to film all three movies simultaneously, then release them back to back. That's what I'd like to do." [...] Jim will be writing case books 16 through 20ish all at once, then releasing them six months apart. Then, taking inspiration from Jackson's treatment of The Hobbit, Butcher will split the final Apocalyptic Trilogy into fifteen books, also written simultaneously and released on the same schedule. Look for "Peace Talks" on April 1st, 2027.
BigBentley15 [Ryan Bentley]: @longshotauthor what part of peace talks are you writing RIGHT NOW! longshotauthor [Jim Butcher]: @BigBentley15 Murphy's funeral. <.< >.> -.- Fans: O_O
The best(?) part is that by then most the fans know better than just overreacting to anything Butcher says and suspect that some form of Exact Words was at play. Although, trying to figure out that one out is bound to delve into Epileptic Trees territory, meaning that the author gets his trolling done in any case. Well played, Trolling Creator. Well played.
Dead Beat was to come after Proven Guilty, but when his agent told Jim that book 7 was to be his first hardcover book, he was asked if Proven Guilty would have an exciting climax. Comparing a valiant legal fight to save a young girl's life to Harry riding into battle on a zombie T-Rex Jim switched the stories with the needed edits. This led to the creation of Butters character as The Watson to Harry for Dead Beat, a role that originally it was supposed to go to Molly, the rookie apprentice.
Word of God: Jim Butcher is quite often going to conventions or signings or readings, and occasionally pops into threads on his own forums, and willing to answer questions. Most of the time he gives a straight answer, it's because it's information that will not make it into the series. His forums have special sections cataloging various "Word of Jim" posts, speaking on everything from how different wizards may perceive things in the Sight (Ancient Mai might perceive a warlock as a dried out, bleached white tree, while Listens-to-Wind may perceive the same warlock as smelling foul), to characters' pasts (Ebenezer McCoy and the Merlin fought on opposite sides of the French-Indian War), to background information that would explode if Harry knew about it (Ivy's true purpose in the Oblivion War).
Executive Meddling: The series was going to be a more faithful adaptation of some of the first books, but two weeks before starting they got a new producer. Jim describes it better, mentioning that he has seen only part of the series once.