Based on standard storytelling format, it's relatively easy to guess which characters are destined to survive, which ones are destined for the grave, and which ones could go either way. Although, being that this is LOST we're dicussing, there are bound to be many in the third group. Still though, this is who I think survives and my explanation why...
Jack - The Hero. Man of science becomes man of faith, truly repentent, willing to sacrifice himself.
Hurley - Comic Relief... enough said. The comic relief always survives.
And that's it for surefire survivors. I know, it doesn't seem like a lot. Here are your dead ducks...
MIB - Duh
Richard - Representative of the Old Guard. Obi Wan and Yoda had to die, so does Richard.
Widmore - The Mysterious Villain. Or is he actually a good guy? Well, that doesn't really matter, because he's meant to come off as a bad guy. He dies.
Sawyer - The Scoundrel. Similar to Sayeed, he'll go out it a blaze of redemptive glory. This one will be the roughest for the fans to take.
The third group is everybody else, with one caveat...
Kate - A Heroine must survive, and Kate is currently cast in that role. I would say she's the leading candidate to finish in this role, especially now that they've wounded her and turned her into the damsel in distress. However, I think, under the right circumstances, she could be supplanted by Claire (newly sane who redeems herself by turning against MIB), or possibly Juliet (using a plot device which I can't conceive of right now).
What do you think?