This is a real shame to me, because I loved Smith's interpretation of the Doctor, but four years seems to be about as good a run as anyone wants to commit to these days. I get that he probably doesn't want to wind up completely typecast and unable to take other roles, but like I said, I really liked him in the part. What I'm really curious to see is how they handle the regeneration now that they're up to number twelve. Should think something special is in store.
Moffat's leaving? Good, maybe I'll be able to enjoy watching the show again. As an occasional episode writer, he's clever enough to be bearable even though he pulls some teeth-clenching crap every time. As an overarching point of view for an entire series, I can't stand the man's work.
Liked Ecclestone; loved Tennant; was meh on Smith. Though I actually started with the 4th Doctor.