I think that vaughn is alive, and is just in hiding for his protection. Remember when sid was gone for those two years and everyone thought she was dead? Well when she got back and found out that vaughn was married to Lauren, she was royally pissed off. vaughn said that he's sorry but he thought she was dead, and sid said to him, "I would have waited!" Meaning that if she thought vaughn was the one who had died, she would have waited no matter what. I think that vaughn took this to heart and remembered what she said, and thats why he went into hiding because he knew that she would wait for him no matter what. I know this might sound a bit complicated, but i bet you anything that i'm right. and if im not, and vaughn turns out to really be dead, then i will have totally resented ever getting into this show so much, just to be disappointed in the end by some stupid ABC executives. if they were smart and would listen to the shows MANY fans, and maybe put alias in a little better time slot, then maybe its ratings would go up!