After watching the pop-up repeat (and I liked the pop-ups, reiterating the net discussion is kind of interesting) I thought that it's definitely Locke in the coffin. "Neither friend nor family" to Jack. Kate says "why would I?" when Jack suggests she'd want to go to the funeral. Perhaps Locke was forced off the island and committed suicide.
Also the guy who sees Charlie- anyone else get the impression that he was played by Kevin Weisman (Marshall from "Alias")? If he was it would follow that he'll be a more important character later just as Dave was a recognizable actor.
I am liking the show - I might get bored with it again - but it's raising some interesting questions.
And I liked Eli Stone - I watched it before I watched any of the LOST episodes, so I hadn't seen any of the commercials. It's reminiscent of Wonder Falls - although not as clever.