I was able today to get hold of an advanced copy to the Comic-Con Special Edition of TV Guide.  My copy has the gorgeous Winchester Brothers on both the front and back cover, Dean in front in the front cover and Sam in front on the back.  The magazine features some big sections for "The Big Bang Theory," "Fringe," "The Vampire Diaries," "Person of Interest," "Nikita," "Children's Hospital," and of course "Supernatural," as well as previews for new shows "666 Park Avenue," "Arrow," "Revolution," "Cult," "The Following," and plenty of DC animation.  

The "Supernatural" section is 8 pages long.  It features the following:

- "Blood Brothers" - an interview with Jared and Jensen by Ileane Rudolph (no spoilers)
- "The Many Faces of Evil" - a look at the "Supernatural villains by Ileane Rudolph
- "Blood/Alcohol Content" - a breakdown of shooting the swordfight scene with the Shojo in "Party on Garth" by John Hogan
- "The Devil Is In The Details" - a "Supernatural" trivia quiz by Alice Jester (gee, I wonder who that could be???)
- "Burning Questions" - a season 8 preview interview with executive producer Robert Singer by Ileane Rudolph

All of these are a blast to read, but this is the Spoiler page.  Only one coughs up what you're looking for.  Spoilers!  I'll share the interview in full on Wednesday when Comic Con starts, but here's the highlights of the Robert Singer interview in which he shares some very spoilery details.  Total, full credit for these spoilers and exclusive rights goes to Ileane Rudolph and TV Guide.  Anything is quotes is from Robert Singer. 

-  Will season 8 hinge on Sam trying to save Dean from Purgartory?  "No," Singer answers.  An amount of time passes before Dean finds his way back from Purgatory (not specified how long).  They're planning on doing various flashbacks through the season showing what happened and what Sam did in that time while Dean was away. 

-  Why use flashbacks?  Because fans usually hate it when the brothers are separated, so that's why they're being reunited quickly. 

-  What about Castiel?  They're still framing that out, but Cas will be back a number of times. 

-  Will Kevin the Prophet be back?  "Kevin is an integral part of the year." 

-  What does Crowley want with Kevin?  The King of Hell needs someone to read the word of God.  "Every year we start with a theme -- this is our "Raiders of The Lost Ark" year.  This season-long story will be a quest.  It's about Kevin and the tablets and the Word of God."

- They would like guest characters like Sheriff Mills, Charlie and Garth back, but nothing is concrete yet.  "And there's one new character that we're talking about.  It's a monster that Dean meets in Purgatory." 

-  Who will be the big bad this season?  It's another angels and demons year.  "It's not apocalyptic but about who can gain control and keep demons in Hell or angels in Heaven."

- I know a lot of you have been waiting for this answer.  I'll share the whole thing:  

Former producer Jeremy Carver, who exec produced the U.S verison of Being Human, is returning to Supernatural as your new co-showrunner.  Will fans notice anything different?  

"No.  Jeremy gave us a couple of years on the show, so I do think this season will be a little less earnest and a little more the kind of stuff we did in Seasons 2 and 3, before the weight of all the mythology got us."  

Okay, start speculating!  I'm 100% certain more details will be surfacing in the next week, especially next Sunday (July 15th) when "Supernatural" has it panel at Comic-Con, but here's your start.