Episode titles for 5.11 to 5.16 have been released by the CW. Source SpoilerTV. I have also included whatever information I could dig from the internet including some of the latest interviews with Sera Gamble, Misha Collins and Julie McNiven.
5.11: Sam, Interrupted (21 January 2010)
Directed by James Conway.
Written by Andrew Dabb and Daniel Loflin
In an recent interview with Sera Gamble, she said "..the boys are contacted by a hunter who had worked a case that was so traumatic that he went crazy. He’s been voluntarily living in an insane asylum and something not right is happening there, and he calls the boys. So Sam and Dean check themselves in...."Dabb and Loflin wrote Yellow Fever, After School Special and Jump the Shark in Season 4. They also wrote I Believe the Children Are Our Future in Season 5.
This episode looks super intense to me, which is different, because in the past, when the show came back from the winter hiatus, we often get fillers like Ghostfacers (season 3) and Family Remains (Season 4). They are great episodes, but when we come back from a long hiatus, we want something a bit solid.
5.12: Swap Meat
Director: Robert Singer
Writers: Andrew Dabb and Daniel Loflin
Also from Sera's interview: "We’re also doing a body swap episode, Sam with a human—that’s all I will say. Fans have been clamoring for it for five seasons. The last thing I can tell you is that we will be further exploring the secrets of the Winchester family and Sam and Dean’s past. There’s more to reveal there."
More secrets about the Winchester Family? Holy crap!
5.13: Back to the Future II
Directed by Steve Boyum
Expect to see Anna returns. She will go back to the past and tried to kill young Sam. We will also see the young/ newlywed Mary and John.
There are some minor spoilers on this particular episode from the latest interview with Misha Collins and Julie McNiven. Check it out here.
I love the Winchester Family centric episode (like Home and In the Beginning.)
5.14: My Bloody Valentine
Your 3D glass is required to watch this episode.
From Sera's interview: "We will be doing a very dark and sinister Valentine’s Day episode. It’s an exploration of the nature of love and desire, which can be very destructive."
Update: Info on casting call
This episode is looking for Famine (one of the four Horsemen) and Cupid. Details here. TV Guide also posted a bit more information on the casting. Read it here.
5.15: Dead Men Don't Wear Plaid
I haven't heard anything major for this episode. There were some casting calls, that's about it. SpoilerTV.
5.16: Your Whole Life Flashes Before Your EyesSounds like this could be an episode where the boys will see heaven. That's my guess.
Source: SpoilerTV, Wikipedia and IMBD.