I missed out Hugo's 'Charlie visitation' from Beginning of The End:
Deceased Charlie > Hurley
Just like the others, 'Charlie's' visitation of Hurley certainly had an influence of re-shaping Hugo's willingness to return to the island
Hurely later tells a defiant Jack:
"Never say never, man"
Does the island play it's metaphorical game of chess several moves ahead, thus allowing it to predict which pieces it will have to sacrifice to best-fit it's chances of survival/victory/whatever?
Being dead in Lost still leaves you in play..I guess the usefulness of those dead souls depends on who they were closest to. For instance, if you're a friend of Locke and you're now dead..then your value is going to be incredibly high..as we saw with 'Boone'.