The episode didn't touch on a few things, such as:
-Desmond leaving the hatch.
-Sun burying the bottle.
-Shannon getting shot.
-Eko and Charlie looking for the plane.
-any showing/talk about the monster.
-Charlie hiding all those statues and his subsequent hallucinations.
-Claire, Kate and Rousseau looking for the medical hatch.
-Hurley seeing Dave.
Really, the episode focuses a lot on Michael, Jin/Sun, the Jack/Locke feud, and Hurley/Libby.
They even flashed back to some parts in season one, such as the blowing open of the hatch, and "we gonna have to take the boy" (my personal favourite quote from season 1).
I can understand why they didn't show everything, we've already had one flashback episode this seasn.