I can't elaborate on it at all, but the one thing I got strongly out of this episode is a hearken back to the old "they're in purgatory" idea. It can't be a coincidence that Charlie and Desmond had to almost die to experience the world we have been seeing for the last six years. Near-death experiences of the afterlife? Makes me think the flash-sideways universe might end up being the real one and maybe these characters are dead after all.
It seems to go both ways, though: Juliet asking someone out for coffee as she dies back in LA X. That was definitely foreshadowing of Charlie's near-death experience of seeing his "true love".