Cop-out... Disappointment... Cheated... all words out of my mouth in the past 13.5 hours. I think the writers knew from the beginning they wanted the concept to be purgatory, but when people threw it out there after the beginning of season 1, they had to reinvent the concept and figure out another way to be able to say it wasn't purgatory, but still run with their original concept. To have the sideways world be purgatory left me feeling cheated. The episode itself was great... The reunions in the sideways world left the hairs on my arm standing straight up - however, some were a little predictable. And then there's Jack's son... I don't think anything on a tv show has ever irritated me such as Jack's son. I started complaining about this last night in the chatroom I was in but I don't think my points were fully understood. All family ties carried over the alternate timeline - Jack/Claire, Sayid/his brother, Danielle/Alex, and Ben/Roger... So you would assume that everyone was still related in the sideways world that was related in the main timeline. Now you have Jack's son... WITH JULIET!!! But they didn't have a child in our real timeline. I would have made more sense to me if Sarah had been the mom and then we would have been told that the child Sarah carried when we saw her pregnant was really Jack's.
What I did like was everything from the flash sideways EXCEPT the last five minutes. I loved the fact that everyone had their happy ending without needing the island like they did in our main storyline. Claire and Jack are loving siblings, Claire and Charlie will be a family with Aaron, Juliet will be with Sawyer, Jin and Sun will live to take care of their daughter, Hurley is happy with Libby and has good luck, Locke can walk and has Helen, Desmond's with Penny, etc. It made me realize that the only reason our friends found any sort of peace or happiness was because of the island but also made me wonder what their lives would have been had Jacob never interfered. I originally thought that the sideways is what that was - but now that it's purgatory, of course it's going to be everyone's happy life because they made it.
Overall, 2 hours 20 minutes of GREAT tv... 10 minutes of total crappy copout bullcrap!