As for Matt Smith's regeneration, the way Eleven has been talking and acting since "The Snowmen" has me thinking that he will buy it at some point saving Clara's life. He already blames himself for her Victorian version's death and Oswin saved his life in "Asylum"....he'll give up his life before she dies again. I'm sure of it.
I have to admit it does kind of seem like it's heading in that direction, with this season being Eleven's swan song. Although I really hope it's not
, because I'd still love to see a lot more with Smith and Coleman together.
Of course we know he's in the 50th special after the Trenzalore episode, so presumably he at least survives that