Ok, so this is something that I've been thinking about for a while, but unfortunately it has little to do with the "Lost Horizon" theory.
It seems that if one dies on the island, of if your body is there, death isn't the end: there's something else that happens to you, or you're not necessarily dead, or something. Here's what I'm talking about:
1. Dead people have been seen on the island. These are people who have died there, or they're bodies are there: Jack's Father, Eko's Brother Yemi, and Boone.
2. The Whispers. People contributing to lostpedia.com have deciphered what is being said during those moments. Just before Shannon died, we heard Boone's voice say this: "Shannon, meet me on the other side." Could the whspers be the voices of the dead?
3. Eko's death scene. When he went out, he had a smile on a face and said "you're next," as if to say that what was awaiting him and all others on the island who die is something profound and beautiful.
4. Ben on the operating table. Just before he was put under, listen to what he says and watch his expressions. He's anticipating something huge. He even says something like "After this, everything will be different" (feel free to correct me on this). It seems that Ben was looking forward being transformed somehow, perhaps looking forward to death.
5. Bea asked Mikhail to shoot her. She seemed awfully enthusiastic about this, and Mikhail was quick to give her what she wanted. Why was she so willing? What does she know that would be so threatening to the others that she's better off dead?
6. And finally, what about Mikhail? When Locke threw him into the sonic barrier, he told Locke "thank you" before he keeled over. Of course Mikhail and Bea could just be damn fool fanatics, but I think there's something more to this.
