The producers are cautiously approaching the story idea of God who 'has left the building' throughout most of the show.
Two things that "Supernatural" will offer a lot in the fifth season are the re-appearance of old faces and a bunch of new but interesting characters. During the show's panel at San Diego Comic Con, producers Eric Kripke and Sera Gamble, supported also by screenwriter Ben Edlund, explained that mythological creatures from the bible and even God himself may come at some point of the show.
Since the new season will jump on the apocalypse wagon, The Four Horsemen of Apocalypse is part of the plan. Kripke joked that these people will be modernized, saying "The Four Horsemen are not going to be riding horses but color coordinated muscle cars. Why ride a horse when you can be in a Mustang?"
About the God's part, Gamble explained that they are "approaching it cautiously". She said, "There is a lot of doubt because a lot of characters are angry at God for not stepping in and doing something about what's going on." During a backstage interview with E! Online, Kripke shared, "I'm not going to reveal how or where, and he's not going to thread in anytime soon, but this is the big season and we felt we couldn't bring on the devil without bringing on God, too, and again, it brings us no end of amusement that our little show has these characters and we're asking these kinds of questions."
Another tidbit coming from the writer's room is the possibility of having celebrity ghosts. One icon mentioned was ex-U.S. president Abraham Lincoln.
On which actors are returning for more action in season 5, the producers can confirm Alona Tal (Jo Harvelle), Samantha Ferris (Ellen Harvelle), Adrianne Palicki (Jessica Moore) and Steven Williams (Rufus Turner). For one thing, they only got into production up until the sixth episode, thus the future is not foreseen.
The "Supernatural" panel was missing the lead stars Jared Padalecki and Jensen Ackles because they were catching up with the shooting schedule in Vancouver. Two other stars, Jim Beaver and Misha Collins however, were present in support.