Re: Time Of The Doctor Trailer!
I doubt Capaldi will appear halfway through the special. Indeed, cliched as it may be, the regeneration happening at the end does serve its purpose as the catalyst of drama, by allowing the rest of the story be the fitting end for the given outgoing Doctor.
"Spock...?" Kirk said, whispering.
"I am... most pleased to see again, Captain" Spock formally replied.
McCoy shook his head in disgust. "Oh, for crying out loud, Spock. Its been eighty years!"
"Seventy eight point four years, Doctor."
The Holy Three meet again, in The Return