Personally, I want to know if Jim was getting bored writing TDF over the last few books (prior to Changes). I can't say specifically what it was, but with Small Favor and Turn Coat, there was just something that seemed like Butcher was going through the motions with some of it. Almost like he knew what he was going to do in Changes, but had to finish a checklist of plot points before he could advance the story.
I really felt it in certain things, like with Molly's development, then regression, and back and forth; and with the scenes with Molly/Mouse/Luccio/Morgan in Turn Coat; and even from the rumor I heard about the fact that he wanted to name Ghost Story something else, but was more-or-less railroaded back into the Two Word title. I feel like he wants to shake things up, and if so, then it's his darn series, so let 'em rip!