As much as I'd like Jin to be alive I think I would be disappointed in LOST if they write some crazy loophole into the story to keep him on the show. I love how unpredictable it all is and never knowing if what you are seeing is reality, but when you see Jin on a freighter that blows up it doesn't seem very likely that any of the islands tricks would be able to protect him. Unless they allude to his survival in previous episodes, I don't want them to say "sorry, we were tricking you again!" The way they have Sun going around seeking revenge, I think that is our clue that his death is meant to stick.

...just watch him come strolling onto the island at the start of season 5.