This is the proverbial Episode That Changes Everything. It’s a little maddening that it might also be (in fact, probably is) the series finale. Arrgh! Curse you, Fox Network, for your sudden yet inevitable betrayal! 
Seriously, though, this has got to be one of the best written maybe-series-ending episodes ever. It leaves many things to explore if the TV angels intervene; third season promises to be as good or better than the second.
But if this is the last hurrah, well, it ended well. There isn’t resolution but there is closure, of a sort. People have ended up in a space that makes sense for their characters. John being unknown actually works well: For the longest time I wondered how the heck he could rise to the position he does. Now we see him, maybe, at the very start of that arc. He survives Judgment Day by skipping over it. Along the way, he’s learned the important lessons he’ll need to take humanity through this challenge. Meanwhile, back in the past, Sarah has done her job and readied her son for his role — and now she’s done the hardest part, the part she’s been trying to do for at least three episodes: She’s let him go.
As a final note, major props to Bear McCreary for scoring a truly devestating use of the Sarah Connor Theme during the pan over John’s not-exactly-resurrected family in the future. If I didn’t know better, I’d say this piece was crafted for exactly this forlorn, unsettling sequence. It’s a fitting goodbye, if need be, to Sarah and her adventure: Regret, determination, and just the smallest quantum of hope.
Pretty much all we ever have to go on.
