A few thoughts about earlier comments:
re Penny's dad and the water: do you think the water would cause it? or was he just inattentive? it did seem odd when he walked out, but i thought he was just being entitled
Re time travel: Fate doesn't allow you to change History (hence Charlie's inevitable death), but it does apparently allow for small blips in history that may need to get reconciled by the time you reach the date that you went backward. I don't know if Fate would allow you to buy Qualcomm in 1996, however, and then short the tech sector a few years later. This would provide Ben with some walk-around cash. God only know what happens when you get to the date of the flight. do you get on flight 815? and if so, are you careful to bring along your favorite nicknacks? or do you just die?
Re. Desmond: didn't he get a lot of electromagnetic exposure when the station blew up?
While I was affected by the intensity of Des' love for Penny, the need for a stable object seemed a bit thin. If Penny hated him in '96, why would she be on the video in 2001/2004 looking for him at the moment that Charlie was calling? Makes me wonder about her; pennies do have two sides, and she is her father's daughter.
And I agree, how do you cast the show's most recognizable actor into a cool/quirky role and then kill him off? I agree that he must play a role beyond demonstrating Desmond's fate if the call to Penny ends with an answering machine beep.