Thanks to ackermaniv for the following.
“Cuse hints that “the journey about how those six return to the island” will be a major thrust of Season 5. Adds Lindelof: “You have to break your characters up to create conflict… but you can’t play that too long because the audience will get frustrated…. And we have that intensely in mind as we proceed.””
Cuse teases we’ll see more of Daniel Dae Kim “in some form” this season despite Jin’s apparent death.