Oh snap... boat people. Neat. Why did Rick smile? My hypothesis: because he's found his army. (un-spoiler, this is not from the comics so my guess is as good as yours. Actually, that goes for everything from this episode, it's all new to me).
On one hand, I'm a little uneasy about Daryl's quick recovery. There's of course room for this in coming episodes, but he's already pretty much acting like himself. I don't want an "emo Daryl" episode, but the way the show's writers did him, it was HIS idiot outburst that got Glenn killed. Everybody else forgiving him and moving on? Sure. You got to. But Daryl? I don't see how he's any semblance of himself knowing what he caused. I'm looking for redemption first.
The "get all the explosives!!" scene was neat and obviously super foreshadowing. Apparently the Saviors dedicated a CRAPload of resources to killing part of this herd, because Rick & co. now has a LOT of explosive to play with. Their trail was conveniently but believably covered... as long as I don't try to think about what might have triggered the "bad" dynamite.
King Ezekial and co. are cool. I like them all. Look forward to seeing more of all of them.