The 100th episode will be a big one for Jensen: He's directing it, and the story will revolve mainly around Dean. Thanks to EW's Ausiello for this spoiler:
Time flies when you’re battling demons and preventing apocalypses and stuff. Case in point: Supernatural will celebrate its milestone 100th episode this spring with an hour that focuses largely on Dean (Jensen Ackles).
“We’re aiming for it to be a big mythology episode,” reveals Supernatural boss Eric Kripke, adding that, “The Archangel Michael plays a very large part as we explore his relationship with Dean.”
But what form will Arch Mike take? The comments section is currently accepting your predictions…