I thought there would be a little more progress with the Oceanic Six, but really, they crammed a lot of story into a very brief amount of time (no more than 2 days or so in show time).
On the island, Charlotte’s nose bleeds are, in my opinion, a portent of the deaths of everyone on the island (an event that has been foretold multiple times). Her symptoms are very similar to what was happening to Desmond and other people on the freighter in “The Constant”, and I think the time travel on the island is going to start to mess up a bunch of people.
The one thing that really intrigued me is that when Locke met up with Richard Alpert during one of the time travel incidents, Richard seemed to know exactly what was going on with the island. I’m not sure exactly who Richard is, or what he represents, but I feel like at this point his character is the key to unlocking all the secrets the island holds.