Ok, ok, ok. I know what youre going to say John Hurt is The Valeyard, so Capaldis Doctor wont get to square up against him. However, Id say I disagree I think Hurts an earlier incarnation of the Doctor, possibly the one who instigated the slaughter/perpetual banishment of the various sides in the Time War. That would certainly explain why Smith seems to know who he is, and what his history is. I know I might be wrong, and you might have a crack at me in the comment sections, but Im willing to nail my colours to the mast over it. So with this (hypothetical) situation in mind, the Valeyard is very much still in play, and usable within Capaldis stint on the show. Personally, I think it would be brilliant to see him go up against the Doctors unique foe his future. Obviously we dont know anything about how Capaldis Doctor is going to act, but if they dont use any of that dark intensity hes brought to his past roles Malcolm Tucker, anyone? then surely you can argue its an opportunity missed. To see Capaldi don his furiously dramatic hat when faced with an omnicidal version of him would be a definite reason to tune in for the next season, not that many people needed convincing anyhow.