Wow, there sure has been a of of hating going on in here. :-)
I, for one, quite like the finale. It was not what I expected it to be, nor did I so definitively like it right after I saw it, but the more and more I reflect on it, the more it grows on me. I keep pulling back more layers, and realizing how many aspects of the show they incorporated into the end.
A forum post a friend sent to me (here, by "John Harker") touched on something I've been thinking about, which is that the finale felt strange because of the overall lack of mythological explanations. But I loved its point about "Everything on the island, happened. That was the factual events of Lost. The sideways was simply the close of our character's karmic cycle".
An article that really piqued my interest (and speaks to some of the points discussed over the last few pages of this thread) was one that was reportedly written by one of the show's writers. It's a good read, and talks about the mythology and philosophies of the show as a whole, as well as how the ending plays into the meaning of the series as a whole. You can read it here.
The conceit that the writers created, basing it off these religious philosophies, was that as a group, the Lostaways subconsciously created this "sideways" world where they exist in purgatory until they are "awakened" and find one another. Once they all find one another, they can then move on and move forward. In essence, this is the show's concept of the afterlife. According to the show, everyone creates their own "Sideways" purgatory with their "soulmates" throughout their lives and exist there until they all move on together. That's a beautiful notion. Even if you aren't religious or even spirtual, the idea that we live AND die together is deeply profound and moving.
Got to run at the moment, but thought I'd throw these into the mix for now.
Take care,
Sojourn