The Name Game: We never do learn the canonical name of CJ or "Esau"/The Man In Black. There are all sorts of supernatural reasons (from Hashem to the tetragrammaton, from Rumpelstiltskin to Voldemort) why that's awesome, but there are more long-suffering-Lost-fan reasons why that sucks. That's sort of how I feel about this whole episode. There's a lot in it. We certainly get some answers -- but why this way, and why now? I'm not the first to say it, but that won't stop me: I don't like where this episode fell in the season. Put this after, say, "The Substitute" and I'm right with you. But putting it after "The Candidate" -- after we've lost Sun, Jin, Sayid and possibly Frank -- after it's clear that Smokey/Faucke is up to no good? It just undoes the pacing of the whole season. Now, it's not over yet. After the finale, I may well look back and decide this had to happen now. But I can't flash forward to after the finale, and in the now, "Across the Sea" is a letdown -- not a breather -- an actual letdown.
That said, I appreciate a few thing about it. I'm glad that some of the answers weren't provided -- that the facts were presented in mythic form. To me, this story of castaways and Others has been going on since there was an island, or that warm wet light, or whatever. All of this has happened before and it will all happen again. Was there a Smoke Monster before Esau? Probably. Was CJ one? Who knows? Maybe. It certainly explains how she made such quick work of Camp Nameless. I don't think it matters, though -- that is, it doesn't matter to me. The version of the Smoke Monster that matters to me is the one that took over John Locke's body, and he matters because he's been tormenting our Lostaways since 2004. I also appreciate that both Jacob and Esau are neither strictly white nor black. The shades of grey (Jacob's temper; Esau's hunger for freedom and truth and rebellion against a pack of lies and manipulation) -make them both more accessible and understandable.