The nice thing about British series is the eye towards tight continuity. Shows like "Doctor Who" or "Torchwood" are less the norm than the exception that proves the rule, and even they tend to keep to a central theme or story arc. "Being Human" has found a proper pace this season, and even better, it keeps delivering surprises.
I mentioned in the review for the season premiere that I was never a fan of Annie, and while this episode didn't change my mind overly much, it did make me care about her fate. I liked the idea that Annie was more corporeal that before, and able to interact on a more meaningful level, and ripping that away from her was particularly harsh. More to the point, it drove home the notion that Annie is no different from Mitchell and George; she, too, must face the consequences of her choice at the end of the first season.
I really didn't see Nina's breakup with George coming, since they seemed to come to terms with each other at the end of the premiere, but the scenario made sense. And it also gives us a character that we care about that has fallen into the direct crosshairs of the religious organization dedicated to dealing with the supernatural threat (they really need a name, don't they?). While her reasons made sense in the context of George's decisions, it is unfortunate.
But it does highlight the fact that George is now firmly enmeshed in the fallout within the vampire community. Mitchell and his allies are going to have a problem with Ivan and his faction, I believe, and that makes perfect sense. As I said in relation to "True Blood", when it comes to this sort of premise, I really enjoy seeing how these supernatural species develop societies of their own. I really want to see how the politics of the vampire world play out in "Being Human". (Especially if that means more Daisy!)