I can just barely remember the episode the Morales family was in. Morgan and his kid, I can remember. Mainly because Rick has continued trying to contact them from time to time. Having Merle back should be a hoot. I predict some male bonding between him and T-Dog. And in a way, he's already been back once (when Daryl stabbed himself with the arrow and was hallucinating).
I don't know anything about this Michonne character. But my guess is, she'll walk with Andrea for about twenty minutes through the woods. Then after Andrea gets on her last fucking nerve (as she has mine since Day 1), hopefully Michonne will slice her head off in one smooth move. If she does that, she'll be my favorite character from now on. Whoever kills Andrea will be my favorite character!