I just watched it and while I didn't like it because it's production values and acting were lacking it is extremely spoilery. Someone on the crew must have read an ARC because they throw stuff in there that goes beyond the 5-6 chapters Butcher usually releases before a Dresden release. Now if you don't care about some spoilers go ahead and watch it, but if you are like me and don't want to know ahead of time whats going to happen do no watch it.

EDIT: Apparently the people who made the trailer made it in collaboration with the publisher and Butcher endorses it so that is probably how they got a lot of the info.