Matt says he did all his own stunts for the Christmas Special.
trailer starts at 2:50
I’m liking the plot description. Should be a fun Christmas episode. BBC America is running it the same day too. 
A few pics here.
http://www.thesun.co.uk/sol/homepage/showbiz/tv/3961163/Xmas-Doctor-Who-will-be-explosive.html
Does he meet C.S. Lewis in the Xmas special?
Do we know if Karen Gilan and Arthur Davil are returning next series?
They mentioned a Karen/Arthur Cameo in the Christmas special.
I’m guessing that’s to remind us they are still in the show? It did seem like their story wrapped up last season. They could still have new adventures with the Doctor. I’m just relieved that the Doctor looks the same in the pics. I wasn’t sure what they’d do after last seasons ending.
Who’s that? 
Author of The Lion, The Witch, and The Wardrobe and all the other Narnia books (after which the Doctor Who Xmas special title is modeled - The Doctor, The Widow, and The Wardrobe).
They are.
BBC has posted the Christmas Special Prequel.
http://www.bbc.co.uk/doctorwho/dw/videos/p00m7qjb
Thankfully it’s not blocked for those of us in America. 
And there’s more Narnia references in the trailer.
“It’s a forest in a wardrobe in a sitting room! What do they teach them at these schools?” 
Really?