The one that comes out of the 'restroom' is supposed to 200 years younger (though both could have lied).

Note that Elvis is painted on the door he walks through (as everybody knows the King faked his death) ;-D

Moffat has been very cheeky with this season.

He has thrown in enough fuel for a thousand good fan theories for some of the big reveals but of those that have been revealed none of them have been big twists.

River can't be .... that's too obvious, River can't kill ... that's too obvious.

So far the twist seems to be there is no twist.

If they couldn't give last weeks story the sort of edge that the tone of this half would seem to have demanded I don't think the Doctor is really going to get killed (though 200 years of blanks to fill in could still give the show longevity if they did the unthinkable...which of course the wouldn't...right?).

You have the possibility of a ganger Doctor...that's too obvious...a red wave time duplicate Doctor (as in The Girl Who Waited) that might be a bit obvious but it would explain the added years...a tesselecta duplicate...too obvious again but as we have seen too obvious might just be the truth.

Maybe their are loads and loads of duplicate Doctors at play here just to confuse us.