For an episode that didn't have a lot happening, I rather enjoyed it. The main focus was Charlie making his list of his "greatest hits", the highlights of his life. The earlier incidents were the focus of his flashbacks, including him rescuing Nadia (Sayid's Nadia) from a mugger. The top highlight was, of course, meeting Claire.
Jack's plan is to blow up the Others when they come to take the women of the group. It's a resonable plan, though I don't know why he had to drag everyone out to the field to show them a tree falling down. I'm sure he could have just explained it.
So there's a new station, the "Looking Glass", and the symbol is a white rabbit. Interesting. Sayid's plan to get to the station sounds solid, but there's that little issue of the water.
Ben decides to go get the women, now! I don't think that Locke getting the tape recorder was part of the plan, though you can't believe anything as far as Ben is concerned. I still see Locke being part (or all) of the cavalry riding to the defense of the Losties, perhaps using that submarine?
One didn't think Charlie was going to die, just because they built it up the entire episode. Deaths on LOST tend to be quick and surprising (Locke, Boone, Shannon, Ana Lucia). So when Charlie surfaced inside the Looking Glass, he was surprised but not the audience. The surprise was the two women, who you have to figure are working with Ben. But why did Ben tell everyone the station was flooded? It's probably a control thing.
You also figure the Looking Glass is going to be around for a while. A production company doesn't invest in a set like that for just one episode. Perhaps the Looking Glass will be the site of many episodes in Season 4. I still like my "volcano blows, everyone gets on Naomi's boat" theory, but I think the chance of it happening is low.
In the finale, there's going to be a lot happening. A Jack/Ben showdown, Locke probably returns, Desmond goes to get Charlie, and some deep dark secret in Jack's past is revealed. Is this secret part of the "Snake in the Mailbox"? Who knows. It's almost impossible to avoid spoilers so I've laid off the nets because I want to be truly surprised come Wednesday.