This episode in my opinion, was clearly the part where we all know the best of the series is finally here. I mean, everyone is back together in one group living on the beach, the survivors are happy, except for Shannon's death, and John Locke and Eko finally found some more news dealing with the hatch. The future of this project, sure is in their hands lol. Desmond is gone, as Michael asked. Now, it was great and very ideal to see a flashback on Kate. It has been quite a while. Her whole original crime being revealed was revealing, and interesting.
As for Ana-Lucia, I like her. I think her evil doing times are truly over. She's a much nicer person at the moment, she was innocent over Shannon's death, so there is no reason why to hate her.
FYI, Kate's whole experience with the black horse and Sawyer acting like a Wayne, was very interesting, and it builds on to some of the islands secrets. The best scenes of this episode were Eko, John and Michael trying to solve the missing pieces of the missing pieces of the Dharma clips. The final scene, showing Michael at the computer and in which we all guess that Walt is really the guy who was talking to him, I was shocked. Truthfully, I know that is not Walt, no kid could type that fast unless he was some braniac. I reckon this could be disastrous, if Michael continues chatting, which he will of course.
Overall, a very superb episode and it showed me that the best of LOST has finally arrived. Very good week of Lost.