But now I want to squee!
I didn't expect that Moriarty was going to be revealed! I thought that was going to be the cliffhanger, that he'd show up and we'd see Sherlock's reaction and then it would cut to black. I DEFINITELY didn't expect that Moriarty was going to be Gay Jim! Amazing. I haven't had a chance to go back and watch that scene in the lab from the beginning of the episode, but now I can't wait to see what kind of subtext there was.
I have to say, props to that actor, because he actually made Moriarty scary. Normally with arch-villains, I don't really ever fear them. They're never as awesome and imposing as the hero, and we know everything will be all right. Even though I'm familiar with Reichenbach Falls and all that, so I know Moriarty canon-wise is to be feared, I've also never really been that frightened by him in film. But this Moriarty? Was creepy, and amazing, and I'm so looking forward to next season. (Which will air in, what? 2020?) I seriously can't believe I didn't get spoiled, though. Cheers to you, Sherlock fandom. Well played.