Great Episode.
Sayid dying to (try) and save everyone else was great. He had been blindly following Locke for a bit, but Desmond got him thinking last episode, and he finally saw that Locke wanted them all dead so he did what he had to to save everyone else. Heck, he had already died once and was "living on borrowed time" anyways. I wish he had a bit better of a send off (a bit more screen time with him getting the bomb away) but still great.
Jin & Sun dying together was sad, but fitting. They both said they would never leave each other again, and they didn't.
Sad about Frank, but these are people living dangerous lives. it's just sad because he never asked to return to the Island. He was just piloting the wrong plane at the wrong time.
I don't think the "Island" was done with any of them, I think they would have all been alright if Sawyer had listened to Jack. It was a fake timer on the bomb. NotLocke tricked them. If they had just left the bomb alone it would not have gone off. Sawyer messing with the bomb is what caused so many of them to die. I wonder how he is going to take that when he regains consciousness? He was really close to Jin. heck, Jin was probably his best friend. And Sawyer got him killed.