I'm not bothering with spoiler space or code, so deal 
Will Jin be back?
He was at the back of the boat... he may have gotten "blown off" into the ocean.
Problem being though, the boat exploded, and the helicopter flew back to the island... and then the island beamed out. So by the looks of it the island and everything touching it (including the water) vanished, but the chopper didn't, obviously.
So did the wreck of the Freighter go along with the island, including Jin (either alive or dead)? Or was Jin left floating in the middle of the ocean?
I'm personally convinced Jin is probably still alive.
And a second question:
Sun goes to Widmore. Is she working with Sayid and co, or is she actually now out for revenge? And was her meeting with him prior or after Ben's meeting with Widmore?

Will Jin be back?
He was at the back of the boat... he may have gotten "blown off" into the ocean.
Problem being though, the boat exploded, and the helicopter flew back to the island... and then the island beamed out. So by the looks of it the island and everything touching it (including the water) vanished, but the chopper didn't, obviously.
So did the wreck of the Freighter go along with the island, including Jin (either alive or dead)? Or was Jin left floating in the middle of the ocean?
I'm personally convinced Jin is probably still alive.
And a second question:
Sun goes to Widmore. Is she working with Sayid and co, or is she actually now out for revenge? And was her meeting with him prior or after Ben's meeting with Widmore?