I will say that I like the sci-fi adventure stories better, so I'm excited about the switch back. The individual stories look great too. I love the Daleks and I've been waiting for an episode with dinosaurs for a long time. That's long been overdue. Let's hurry up and get the first episode here already!
 Strictly speaking, justification isn't necessary. The Doctor did lots of killing that didn't get directly evaluated in the Davies' era (e.g., the horrific killing of the Cybermen on the parallel earth). However, given the progression of the show one would expect at least some indirect comment on any killing that the Doctor does.