http://www.newsarama.com/tv/Doctor-Who-Paley-Center-100415.html
I wonder what he means by "cheeky"
A very important aspect of the Doctor’s own past will finally be dealt with this season as Newsarama learned exclusively – The Doctor’s regeneration limit. “It’s been addressed in a very, very cheeky way by an old friend of mine and I’m not going to tell you any more about that,” said Moffat, telling us to “wait and see.”
Something you don’t have to wait for is discovering who the Eleventh Doctor’s Big Bad will be. Smith told the crowd it’s seen in the very first episode. “Albeit, not in the most conventional form. You’re going to have to think about it and find out what it is, but it’s in there,” he said. “And that’s the one, that’s what takes us through the whole series and my god, it’s bad.”
I wonder what he means by "cheeky"