Update: Well, I was totally wrong with my guess. LOL
"The way I see it, every life is a pile of good things and bad things. The good things don’t always soften the bad things, but vice versa, the bad things don’t necessarily spoil the good things and make them unimportant.”
From the Vincent and the Doctor episode.
Okay so this is me waving my Dork Flag really high, but Doctor Who fans will understand.
So I think I figured out who the guy is (John Hurt) at the end of Doctor Who season finale. My guess is he is the Valeyard (learned court prosecutor for the Time Lords). He had appeared in the 1986 episodes of Doctor Who where the 6th doctor was put on trial.
Following is quoted from wiki.It was then revealed that the Valeyard was, in fact, the Doctor himself — or rather, a distillation of the Doctor's evil side, a potential dark version who might exist around his twelfth and final incarnation. This concept is similar to the ethereal "Watcher" that manifested itself to bridge the gap between his fourth and fifth incarnations (Logopolis). However, in the novelisation of the story the Master states "The Valeyard, Doctor, is your penultimate reincarnation... Somewhere between your twelfth and thirteenth regeneration".
Since their bringing back a bunch of villians (possibly for trial?) and the 10th doctor and Rose (*sniffles* I still get teary eyed.)
What are you guesses for the Doctor Who 50th Aniv special?