First, check out this alternative ending: http://ausiellofiles.ew.com/2010/06/28/how-lost-should-have-ended/. Just heaps of fun.
Second, I am re-watching the series as my daughter wants to see the first five seasons, having only watched the last one. Yeah, pretty strange, but if you can figure out teenagers, let me know. Anyhow, it is fun to see some themes emerge, even if it is still pretty clear that the writers really do not quite know where they are going yet. Watching the episode at the start of Season 2 where John Locke is struggling with his father obsession/anger-management issues, and his sweetie, Helen, emphasizes the issues of "letting go" and "asking for help from the community." So, either this was something very much intended or perhaps the writers went back to the show's past to figure out the themes that they would carry forward, especially in the last season--redemption through community and letting go.
So, yes, I am now playing the game in watching season 2 (we buzzed through season 1 very quickly) of: how does this fit the conclusion/did Damon and Carlton have a clue at point x about how this would end? Fun stuff.