This is getting boring.
Let's speculate on who will be the chosen candidate.
Aside from any weird selections (like people not on the list) meant to catch us off-guard, I'm going to put money on (1) Jack or (2) Hurley.
Classical writing is a funnel in, funnel out process.
The end and beginning come full circle, to tie things together like an oroborus.
Picking Jack closes the circle most completely.
Jack was the first character we saw on the show, so it would come full circle very beautifully. He was the first character we knew well.
He had to be the leader, and opposed Locke in pursuit of that role.
There was a lot of narrative mess in the middle, and now things are simplifying again... with jack still around.
Right now, as pseudo-Locke and he are again at loggerheads, face to face, just like they originally were.
When everyone else left the island to steal the plane/sub to go home, Jack went back and is now with Locke.
Just like Jacob and TMIB.
Jack wanted off the island badly because he wanted his old life back.
Once he got off, he realized he didn't want to leave the island.. or shouldn't have.
He's done a big turn-around, and realized that life off the island for him is not as important as life on the island; the others have things they want to return to.
He's gotten a sense of his destiny and that he will not be happy off the island.
Jack has always been the one who fought destiny and determinism, violently.
It makes sense he would be the one who would finally succumb to it and embrace it.
Jack lost Juliette, and he had Kate but it's obvious that won't work anymore either. He has no love interest to go back to/with, while Sawyer and Kate might end up together since they are "kindred spirits" in a sense and deserve each other.
From a writer's perspective, Jack is the character whose dramatic narrative causes the most sense of completion and resonance within the story line, if he is selected. If he is, the series will probably end with him as the last character and things fading back out just as they originally faded in.
As far as Hurley goes, he's the "feel good" choice.
Everyone loves Hurley.
Hurley can see dead people.
If anyone will defend the island with goodness and kindness, it's Hurley.
But Hurley really deserves better.