Not sure how to respond to what I want to respond to, but this is not about how Desmond caused/didn't cause the crash.
My thoughts on the episode:
1) Penelope tells Desmond something to the effect of "anyone with money can find anyone." I believe that somehow Penny found out that she should be looking for magnetic anomalies to find Des, and that is the reasoning behind the monitoring station.
2) Hurley is a huge question mark for me. Why did they insist that Michael bring him, if they were just going to release him? Why did it HAVE to be Hurley, and not someone else? Why was Hurley the only one who did not get shot with the taser tag? (I'm guessing because he's the only one of the 4 who would not fight back, but still seems a little fishy) Why did the giant bird thingy call out his name? Seems like there is more going on with Hurley than we ever imagined.
3) It would not surprise me if Desmond, Locke and Eko were dead. Locke is somewhat of a surprise considering how much of a central character he's been, but it's been all the rage nowadays to kill off main/central characters on TV shows. Although, if Desmond were dead, it would kind of make Penny's search for him seem stale and pointless.
4) I too noticed the looks that Kate and Jack exchanged at the dock, and I, for one can't wait to see what they have up their sleeves. I'm also curious as to the selection of the 4. Jack, Kate, and Sawyer are obvious choices if the Others want to take the leadership/strong people from the losties, but again I ask, why Hurley? A more logical fourth choice would be Locke or Sayid.
Anyway, it was a lot to digest, and I just felt the need to post my thoughts.
Till next season