As usual, the latest issue of Doctor Who Magazine (no. 486) features fans putting questions to current showrunner Steven Moffat about Doctor Who. One fan was curious as to if we were ever to discover the link between Caecilius from The Fires of Pompeii and The Twelfth Doctor (both played by actor Peter Capaldi).
Andrea Laford asked:"I really enjoyed the scene in Deep Breath when The Doctor says to the tramp, "Why did I choose this face? It's like I'm trying to tell myself something..." Will we ever get an explanation of why Caecilius from The Fires of Pompeii has the same face as The Twelfth Doctor?"
Steven Moffat replied:"Thank you, I like that scene too. And yes, we're coming back to that idea. In fact, we'll be shooting the scene in question really quite shortly..."
Source