Future Doctor Spoilers?

Back in May, after the broadcast of Flesh and Stone, we speculated that there was a future Doctor crossing his own timeline in one particularly suspicious scene (see it here at the 5½ minute mark).

TV Choice Magazine has a new interview with Matt Smith which all but confirms this is the case, if you read between the lines.

Asked if Smith knew all along how the series would end, he replied, “No. You get your call sheet and you see Episode 12. But I filmed that when we were doing Flesh And Stone, which was four and five, wasn’t it? But then you’re doing your episode 12 insert at the end of your shooting day.”

“So you just think, ‘God, I’ve got to do this other scene and I’ve got no idea what it’s about, I just know I’ve got to come up and be quite concerned about Amy,’ but I don’t know why. However, it was nice because the Doctor also doesn’t know. He’s always thinking, ‘I’m trying to work it out’. I also think it’s amazing how the magic of time travel is perfectly captured.”

Smith added “[Episode 13 is] brilliant. It’s how cleverly Steven Moffat plays with time, really. That’s the real virtue of these two episodes — Steven’s brilliant mind. I don’t know how he thinks that way.
 
Did he promise a big ending that will surprise everyone?
 Well, yeah. It keeps you hanging on.”