This season was extremely uneven. It really had me worried. The season premiere was great (zombie herd!) but then Carl was shot and Sophia went missing, and it all went to hell. It's interesting that the second half of the season - easily delineated by the three-month hiatus - turned itself around so completely, it was almost like two separate seasons; season 2.5.
The first problem with the first half was a significant lack of zombies. I know that The Walking Dead is as much a character drama as it is a show about zombies - more so, even - and I totally accept that. But I don't find a lot of characters on the show likable, so I don't really care about their inter-character angst. The promise of zombie carnage helps to break up these dull segments. It didn't help that by episode two, Carl was near death and Lori was out of her mind with worry. I find her one of my least favorite characters, so an entire episode about her worrying and fretting was a slow and painful one for me.
There were a bunch of little sub-plots that just didn't click with me. Daryl going crazy in the woods and seeing Merle. Sophia going missing (it was a great reveal when she stumbled out of the barn, zombified, but her story was drawn out too long). Every aspect of Lori's pregnancy. Hershel's holier-than-thou attitude. Shane's "I hate everyone, why won't Lori love me" attitude. In general, the first half of the season had all these problems that, while actual problems that the characters can't be blamed for worrying over, they are passive worries, and that doesn't make for good TV. Carl's recovery was wait-and-see. Lori's pregnancy was a lot of "yes I want it, no I don't" back and forth. Daryl was either going to push the hallucinations out of his mind, or go crazy and succumb to them - that was another wait-and-see.
With episode seven - the mid-season finale - things changed. We had a satisfying resolution to the Sophia story. Hershel was knocked down a couple pegs. Lori had made a decision so we didn't have to hear about it anymore. We instead got to focus on active problems, mostly the issue of Randall and whether killing him was justified or not. He and his friends were admitted rapists, which as far as I'm concerned is justification enough for killing him. But Rick's primary reason for wanting to kill Randall was to protect his group from a potential (instead of actual) threat, and to protect his current way of life. That raised interesting moral dilemmas that don't often get addressed (unlike "who's my baby daddy") and don't require patience for a resolution. Shane's plot to kill Rick was a little contrived, but it ultimately led to a great storyline and a much-needed character shift. Overall, the back half of the season helped me forget the trying first half.
And of course, let's not forget the utter carnage and mayhem that the season finale left us with.