Ausiello gives two more details regarding next week's 100th episode. Although saying we thought the returning person was "definitely dead and gone forever" doesn't really narrow the field on this show!
Question: The recent synopsis posted about Supernatural’s 100th episode has me curious. Do you know who the familiar face is and what the angels’ new plan consists of? —Andy Ausiello: At the risk of someone sending the angels after me, the person is someone you definitely thought was dead and gone forever. And I can tell you how one trench coat-wearing angel plans to stop the apocalypse: beat Dean to a pulp.
While I'm still hoping the returning dead person will be Big Daddy Winchester, rumors are that it's Adam, the boys' surprise brother. And I'm not looking forward to seeing Castiel hurt Dean. I love it when they are two lost souls bonding over the crap the higher powers are putting them through.