I think the worst thing you can do with a pop culture phenomenon is to interpret it for people, or tell them why it's successful or (worst of all) tell people why they really like it. That said, I will share *my* thoughts/reactions/observations to the final episode, simply because I haven't seen this interpretation anywhere in the "mainstream media" (granted I only read 2 - 3 articles.)
I thought the final 15 minutes of LOST was all about the show ending. The church, we're told, is something that was created by the characters, it was something very special they created together and it captured the most important moments of their lives. It's like the show creators are looking back on the show they created (as their best creative work and the best years of their professional lives). With the audiences, they created theories, fan-pages, message boards, and a dynamic 21st century media circuit that connected the show and viewers. (this sort of thing never existed when "I LOVE LUCY" was on TV. The creators of Gunsmoke didn't kill off a character because fans hated the character.) The church is the unique experience of LOST.
At the episode's end, it's time for everyone to move on. The actors will move on to other movies and TV shows (which will inevitably be compared to LOST.) Audiences will have to find new obsessions. J.J. Abrams will move on to gimmicky movies.
For the past 6 seasons, the ABC voice-over (the voice of GOD) would announce at 9pm "an all-new episode of Lost starts NOW!"
Christian Shepard told Jack (and told us) there is no more "NOW". Show's over. Time to move along into an unknown future.
If anyone watched the final episode of XENA WARRIOR PRINCESS you'll know what I'm talking about: XENA has to die, and Gabrielle panics because she's unable to live without Xena. (the same way die-hard fans can't let go.) But Xena gives a speech about how she will live on in Gabrielle's memory, and there's even a whole thing where Xena's spirit is transferred into Gabrielle (which is passed into Gabrielle's body through a kiss!)
Regardless of how I feel about the show's narrative, I find it a little weird that people get so worked up or offended by the way a TV series ends. People were pissed at the Sopranos' finale. (Just yesterday a guy I know said he wanted to "punch David Chase in the face." And to hear him talk about it, he still held a grudge.)
But I think TV shows should be allowed to have wildly imaginative endings. Because believe it or not, I think TV is an artform. (It can be an art, even though it's usually not.)
Stanley Kubrick can end a movie with an unclear conclusion. Why can't a TV show do the same thing?
Does a show owe the audience the ending they want?
Other oddball moments:
* iPad commericials voiced by Peter Coyote (who narrated those turgid hour-long LOST "recaps")
* HURLEY: You were a good number two.
BEN: And you know a lot about good number twos, don't you?
And finally, here's my guess at YOUR response to my interpretation.