Since last year's finale, the big question has been, "Who's in the coffin?". After watching last week's season premiere, I've been really thinking about that question and as of today (Feb 6th), my theory is this:
Locke is in the coffin.
It seemed logical to assume that Jack's group made it off the island, and Hurley must've changed his mind and joined up with Jack and Kate. But what if that's not true? What if Jack and Kate changed their minds and joined up with Locke? Why would they do that? Consider this...
The "rescue" team arrives on the island, and Jack and Kate are thrilled at the idea of rescue. Suddenly, they realize that the "rescue" team poses a threat. So, rather than go with them, they decide the best thing to do is stay on the island, so they join up with Locke. The "rescue" team somehow demands that they come with them, and forcefully takes 6 of the losties off the island-- Jack, Kate, Hurley, Locke, Sawyer, and Claire.
Last season's finale dealt with Jack finding out that "Locke" killed himself, because once he was taken from the island, he lost the ability to walk and returned to his paralyzed state. Of course, Jack blamed himself for that, since he is the one that called for rescue, and he didn't listen to Locke. It would also explain why no one was at the funeral and why Jack said that he was neither a friend nor family.
That's the theory for now.... I'm sure it'll change after tomorrow's episode. And just as a heads-up, the recap for the next episode "Confirmed Dead" may have to wait until the weekend.