Season 3 was when they tried out the first half season to do with this set of characters and this plot; second half for this set formula. But this season I think it worked out better. Frozen for the first half and a medley of Maleficent, Cruella, Ursula, and the Author for the second half. I liked the medley: focusing on a few characters keeps you from getting tired of them before the season's over. And yet there was just enough of a tight focus that there was never too much going on at once.
This whole Author plot felt new and original, unlike what we had seen before in the show: early on when it was still being hinted at, I literally didn't know what characters they were going to bring up and how it was all going to work out. Except for all the Pinocchio hints going on: I did hope they were going to bring August back and I was so much more excited than I'd expected to see him again. It was like I didn't know I missed August until he was back. Now if only they could bring back Baelfire, but I suppose they've emphasized enough that that's out of the question . . .
You know what was a really interesting turn of events? All during this second half of the season (and a little in the first half), there was this idea of the villains trying to turn Emma dark. And it never really felt believable: Emma's not holy or perfect, but she's not dark, either. So I think we knew the plans wouldn't work, and they didn't. But then right there at the very end of the season, she becomes the new Dark One. Ohhhh. That was good. I wasn't expecting that. I wasn't even expecting Rumplestiltskin to stop being the Dark One--but both of these turns of events are going to be very interesting to explore next season. Who will Emma be as the Dark One? Will she be wholly evil, or will she still be partially herself? After all, Rumplestiltskin was susceptible to the bad influence of being the Dark One because he chose to be in that position for the power--by killing the previous Dark One, too. But Emma came into this position in order to spare others: it was a selfless act, not a selfless one. So perhaps that will affect how it influences her. And presumably Hook took the knife and will keep her in line (only that sounds all too easy, doesn't it?).
And who will Rumplestiltskin be? I really enjoyed seeing him go back to his evil, in-control-of-everything self from season 1 during this second half of season 4, but I also like to think that he isn't all evil and won't end as all evil, either. So will he finally get a real second chance this time? Are we going to see him reformed into a good person now? What would he be like as a good person? Would it even work within the framework of the show for him to turn good?
Then we have the King Arthur hints. We'll be seeing Merlin, but I would think that Arthur would also come in. We've seen Lancelot before, so why not Arthur? Will Guinevere be in it? What version of Merlin will we see? What will the timeline be? Yes, I am very excited to see what season 5 has in store.