It's not Vaughn. Think about it. This is the culmination of Rambaldi Prophecies, now concentrating on DNA and life after death. They are not going to waste it on Vaughn. Who would be worthy of coming back? Rambaldi himself, or at least someone much more important than Vaughn.
I can't believe this show went so downhill and it's only the second episode. I had no idea Vartan was leaving. Makes sense though, he can carry a movie. But why did Weiss leave? This is the best job he's ever had and ever will. He only has it because JJ Abrams takes care of his "family". I guess we'll see him on Lost next. Then they come in and bring in 2-3 new characters. Stupid characters too. And judging by that spy chick in the bar, characters that can't act either. Garner must be under contract because I can't figure out why she is still sticking around. She obviously thinks she is too good for this petty stuff. The fame defintely got to her head (read: divorced her no-name husband after she hit the "big time")