Doctor Who?

Ah yes, ladies and gentlemen. The age old question. Whenever someone first meets the dear old Doctor their second question is always "Doctor Who?" (The first being "Who are you?" to which, if memory serves, the First Doctor once answered "Yes, quite right.") It seems as of late it's no longer a running gag and is an actual plot key. For as any Whovian worth their weight in gold dust knows, "Doctor Who?" is The Question. The question "that must never be answered", but will asked at the Fields of Trenzalore, and lead to the "The Fall of the Eleventh". Could this mean Matt Smith's tenure as the Doctor is coming to a close? Unlikely. Matt has signed for 2 more seasons after season six, and I doubt that Steven Moffat will see fit to drag a story arc other than River Song over more than one season. Another reason I personally think this theory is a bit rubbish is because the clue was thrown out there by none other than Moffat himself. The man is a master of misdirection. Remember all that build up with the Gangers, only for the Tesselecta to be the Chekov's Gun that saved the Doctor? Pure Moffat.