Here's my terrible, heretical admission about the last season of Lost: I enjoy the flash-sideways. No, wait, that's not it. What I meant to say was: I don't care if they answer all of the questions about mythology or not.
I can feel your stares of disdain from here, but they won't change my mind. Don't get me wrong, I enjoy the Uber-Questions about the show ("What is the Island?" "Who are Jacob and FakeLocke whose real name I've forgotten if I ever actually knew it in the first place?" "Why is Michael Emerson just scary all the time?") but they're not what makes the show for me, and I can't quite get behind the idea that Lost will somehow be a failure if it doesn't manage to solve every single mystery it's raised throughout its run so far.
(If nothing else, I'm not sure every single mystery has an answer anymore, if they ever did, and for every question the show has raised to be answered, I feel as if the show would have to become exposition central for the remaining episodes, and even then, many would be left unsatisfied.)
I keep thinking back to the finale of Battlestar Galactica, and what worked for me and didn't in that episode. I remember watching for the first time, and feeling completely caught up in the moment, and (for the most part) satisfied with what I was seeing - It was a purely emotional response, a feeling of closure and farewell to characters I'd spent many hours watching and thinking about, and it worked for me, until I started to pick apart everything after the initial rush had gone. Upon distant reflection, a year later, what didn't work for me was the dotting of is and crossing of ts in terms of plot and mythology - the opera house, Starbuck being revealed as an angel of sorts, the epilogue that hammered home that all of this had happened before and would happen again - and I felt as if my initial reaction and subsequent disappointment mirrored the way the story had been put together: Built around larger emotional finales, and the details awkwardly inserted at a later point to provide closure for those who needed those answers. Would the finale have been better if it hadn't tried to explain those things, but just focused on the characters themselves?
(Another example of that might be the end of Grant Morrison's The Invisibles. As someone who followed the original run as it was released as single issues, I found myself so emotionally invested in the characters that it doesn't bother me that, plotwise, a lot falls apart at the end. The emotional throughline, and payoff to a narrative of intent that somehow goes beyond plot detail, felt - and feels - satisfying enough to let Morrison slide on all that was left unsaid and unfinished.)
This isn't, necessarily, an argument for the "But consider midichlorians" school of thought that some things are better left unsaid - That said, how many people are steeling themselves for the reality that Lost's answers won't live up to the ones they've been working on while watching the show for the last five years? I'm already kind of disappointed at the reveal about the numbers, if there's not going to be any more said on the subject - but more one that, like Charlie said the other day, suggests that even a show that relies on mystery and raising questions as much as Lost is really about character. Without our becoming invested in the characters, you're left with something like FlashForward, which tries its hardest but is nonetheless glossily hollow and weightless (Sorry, Joseph Fiennes), and Lost is, at its best, something more than that.
I agree that some payoff for the larger questions is necessary for Lost's finale to feel complete, but I worry that anything more than that will come at the cost of what the show is really about, which is the people onboard Oceanic Flight 815 and those they've met as a result of the crash. Easter Eggs and Fan Service is all well and good, but if Jack, Hurley, Ben, Jacob and the others - even Locke, as dead as he is - don't end up with the ultimate fates they deserve and something that feels right, then the whole thing will be for naught. Lost may have been one of the more thought-provoking shows on television, but personally, I'm pulling for an ending that goes for the heart instead of the head.