It hasn't been completely confirmed, but I think we can pretty much assume Richard came on the Black Rock after this episode. The writers seemed to do a very good job of not completely telling us that Richard was from the ship, but he did say this was the first time he came back. And where else would he want to die on the Island than on the ship that brought him there? That scene pretty much answered the origin of Richard for me.
We also pretty much get the reason why Richard is ageless as well-Jacob's touch bestowed on him the gift of never aging or dying (at his own hand). But it also appears Jacob's touch did that to Jack as well, because Jack wasn't able to kill himself either.
An interesting thought...was Michael unable to kill himself off the Island because he was a candidate for Jacob at one point? Did Jacob come to Michael at some point and touch him, preventing him from killing himself?
I really did like the flash-sideways in this episode, because they paralleled the on-island events very well. In the flash-sideways substitute teacher Locke gives Ben the idea that he could become the new principal of his high school. On the island, the Smoke Monster as Locke gave Ben the idea he could become the new leader of the Island. But in both cases, Ben didn't go for it. His thirst for power didn't come through as much as it used to.
Did anybody kind of smirk when Ilana told Ben, "I'll have you?" Kind of dirty ;)
Loved the Nikki and Paolo reference by Miles.
and...Widmore. Is he the one that Jacob said was coming to the Island? Certainly looks like it.