Re: The Curator.... Who is he? (SPOILERS for "The Day of the Doctor")
I still think he's the 4th Doctor and he is from just before "The Lesure Hive". Why? Look at the scarf Osgood got on. It's the pre-"Hive" multi-coloured one.
[crackpot theory] He gave her his scarf and when he snaped back to his own time stream replaced it with the red tones one.[/crackpot theory]
"I calculated the odds of this succeeding versus the odds I was doing something incredibly stupid, and I went ahead anyway." - Crow T. Robot, Mystery Science Theater 3000: The Movie