My first thought was that it was Saywer, mostly because Jack called Kate. But now thinking about it, why would Jack get all teary-eyed over James? Who would he care so much about that he wants to off himself when he hears that person died.

Juliette would be a good guess. I don't think it would be Jackob because (if he exists) he would never leave the island. Same probably goes for Locke. It could be Rose... if she leaves the island her cancer may come back. That would meant that Bernard would have to die, because he would definately go to the viewing.

I guess we'll have to wait and see.

-- Ok, didn't see the post above. So it's a man... Could be someone we haven't met yet.