It's been confirmed! April 23 is when series 6 is going to start! Also, we have the title for the first episode with 'The Impossible Astronaut.'
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The only bit of interesting news I found is that there are going to be three prequel shorts that will premier on the official BBC Doctor Who site 'soon.' From the sound of things they're going to be more like the Tardisodes then 'Meanwhile in the Tardis.' The first one should be up before 'The Impossible Astronaut' airs and may give us a brief glimpse of the adventure's monster.
Please don't be the Slender Man. Please don't be the Slender Man. Please don't be the Slender Man.