Ben can't go back?

I'm thinking the main timeline will be about the O6 as they got off the island with flash forwards to the coffin scene timeline.

I reckon that where we left it, Jack agreeing to help Ben etc, will be the present with flashbacks to what happened since leaving the island, aswell as flashbacks for the island inhabitants of what happened in the same timeline - and then season 6 will be the ultimate battle for the island.

Yeah, I tend to agree with you SBP.

Because to a large extent we know what has happened to the O6 since leaving the island - Kate survives her trial and lives with Aaron, Jack was involved with them on and off but then lost the plot due to his dad popping up, Hurley the same but with all the other dead peeps, Sayid gets married then Nadia is killed and then he works for/with Ben and we know Sun has her baby and takes over at Paik. Any missing bits such as Bentham visiting them can be cleared up with a few select flashbacks. Otherwise we'll just be going over old ground.

I agree also. I think the 06 story will be about Jack convincing the others to go back. Trying to mend fences with Kate and Sun etc.Maybe their current storylines will coincide with flashbacks/sideways/forwards of the on island situation. I'd like that. It would be a bit different.