Well.....Locke can get off the island as when Ben was leader of the others he went and came as he pleased. I think that this is what made the island pissed of at him maybe and he ended up with the tumour on his spine as punishment. The island heals who it wants and kills who it doesn't. We also saw Tom the Other in New York visiting Michael so people can come and go. Plus it was important to the island for Locke to leave the island and get them to come back.
Lyra...when they were getting onto the life raft and Kate said "he's ok" about Aaron, I shouted "No! He's hungry!" He must be breastfed, he's only a few weeks old (in TV land) but he's been without Claire for a couple of days.
Christian Shepherd obviously is important but I am at a bit of a loss to understand why. Of course he has the Jack and Claire connection but he also met Sawyer in a car in Sydney. Who else has he met that we don't know about. Remember that Jacob said "help me" when he was visited so maybe Christian is the Big Bad.
Claire was told by a psychic that Aaron should not be raised by another. I have started to wonder if this is maybe raised by an other rather than another and this is why Claire doesn't want him to go back to the island.
What I didn't get was why all the Oceanic 6 were calling Locke Jeremy Bentham. Is it cover, as they are being watched and someone might find out that they are talking to someone from the island?
My biggest question was: Is Sun playing Widmore to get revenge or is she using him to get back at Ben for killing (or not) Jin. She was wonderful this epiosode.