For those of you who've read Darth Plagueis by James Luceno, it makes it clear that no Sith can come back from the dead, and Plagueis's plan was never to spirit-hop from clone to clone, but to keep his cells regenerating and keep his own body young forever. He could still be killed by external means, and was, by Palpatine. These dudes have turned the "dark side" into a magic bullet of evil with no rules. Pathetic
