The Supernatural Panel has ended and reports are starting to come in on the spoilers from the panel.

TV Addict has a liveblog of the panel posted here.  From the Liveblog

We were also treated to scenes from the premiere. Dean asks his mother if she’s real and as he approaches her, she takes him down to the ground. There’s a few scenes of Mary and Dean in the car and Sam tied up in the back of a trunk and being burned by a blowtorch. Cas is fighting with an angel blade on a road and Mary seems confused by cell phones. Mary also says “I never wanted this for you and Sam”.

Hurt Sam lovers rejoice!

In regard to Mary's return

Padalecki said that one of the things that SUPERNATURAL has been able to do is to explore “both sides of the equation”. One of the biggest things about the show is family and it will be an interesting dynamic to see someone like Mary who is 100% of Sam and Dean’s blood, we’ll find out more about how family is formed and what it means. It’s about “exploring that dynamic between two brothers and two sons again. Sam always had an issue with John for obvious reasons probably. But he dealt with it. Now Sam and Dean with their mother is starting anew.” Does blood make you family or is it about more than just sharing DNA?
Misha spoke to Cas's role this season

Collins said that Cas is back to a little bit of “Cas from season 4″.  He thinks Cas’ wings are still broken, but he’s got a lot of his mojo. He’s angry and he’s got a fighting spirit and he’s after Lucifer.  Collins also joked that Cas is tattling a lot to Mary.

Collins said there’s an interesting dynamic between Cas and Mary because “in a way we’re outsiders”.

Mark Sheppard said

Sheppard said there’s a hint that “my family dynamic might be returning in a slightly more expanded scale. I genuinely love Ruth, but I cannot stand Rowena”.
That ties into this announcement

Will any old characters return? Jody and Donna will be back, as will Claire and Alex. Gavin (Crowley’s son) will be back as well.


It looks like we aren't getting Mark Pelligrino back as Lucifer. From TVLine

The devil you say! Rick Springfield has been tapped to raise hell in multiple episodes of Supernatural’s Season 12, as Lucifer’s latest vessel.

After taking possession of Castiel’s body in Season 11, the fallen angel is “going to try out a few different vessels” next season, executive producer Robert Singer said during the show’s San Diego Comic-Con panel Sunday. “You need a really strong vessel like Sam, like Castiel… “

TV Insider adds

Executive producer Andrew Dabb acknowledged it's a bit tough to find a legit rocker who can actually act, but Springfield fits the bill. He shot his first scene last week, and "he's doing an amazing job," Dabb said.
TVLine also talked to the panel about Mary's return.

Mom’s comeback “presents a dynamic that we haven’t had in quite a while — or ever,” Jensen Ackles previewed. “When mom left, Sam was a baby and Dean was a child. The children that she knew are now men, so the relationship is kind of nonexistent because there isn’t one. It’s an interesting situation, them trying to bridge that massive gap.”

Buddy TV reports

First off, the folks over at Warner Bros. have dedicated a day of tribute to Supernatural to voice their appreciation for the fan support. September 13, the day the pilot episode of our favorite demon-hunting show first aired 12 years ago, has now been dubbed "Supernatural Day." As if you need another day to celebrate this amazing show.

The Panel ended up trending on Twitter

SPN

Keep checking back. I'll be adding to this as more outlets report in.

Updated:  Here are the Storified spoiler tweets that Nightsky put on the WFB timeline after we got out of the press room.  Some good info!

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UPDATE

TV Addict released an article with more spoilers including

The Return of the Thule. They have something really cool coming up in episode 12.05 – it will be the “triumphant or not-so-triumphant” return for the Thule, who have decided to bring back Hitler. But the SUPERNATURAL version of Hitler is described as a “psychotic Richard Simmons.” Apparently “Sam and Dean are going to find Hitler,” Dabb teased. “And I think that’s opening up some interesting doors for us just in terms of doing more crazy stuff.”


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