The reason everyone watches Lost is not to study the intricacies of the characters, or to have deep thoughts on philosophy or existence. We watch it to find out what's been going on this whole time. The good news is that, moving into the last episode, there's very little that can't be understood. At one point in 'What They Died For', a bunch of the characters are sat down and given a good talking to by Jacob, the old boss of the island. He explains why they're there and what they have to do. Even though we could work it out ten episodes ago. It's not an entirely simple answer but it is a satisfying one. Everything has been laid out in little nuggets throughout the season (apart from the backstory heavy 'Across the Sea'). The answers don't feel like an anticlimax, more like something we should have known all along. The only important question that remains is 'what exactly is this island place?'. I'm sure that'll come up.
The final season has been constructing this 'flash-sideways' story, showing the characters in a different timeline. To the people who gave up on the show a while back, this sounds exactly like the sort of introspective nonsense that they found so offensive. This does have a point though, I'm sure of it. Something is going to happen. Lost has gone down every alley of its story from every different angle, and I'm confident it's all been for a reason. It clicked when we were shown how the tiniest of objects found in a cave in the first season relates to the entire grand story of the island. The writers had this down from the start, they did. Somewhere in the middle they were probably given too much time to faff around, but it's rare for such an expensive network show to be given free reign over it's nerdy mythos. Imagine if it had been cancelled two seasons ago. A decade of speculation would have followed. Lost has captivated enough people enough of the time to make it right to the end.
If all goes to plan I'll write a simple question-and-answer 'what it's all been about list'. For my own mind at least.