It is rumoured (and near enough confirmed) that a returning enemy of the Doctor will be "The Great Intelligence". In a number of trailers, promotional videos and even a promo picture removed by the BBC (See Below) we keep seeing the initial GI.
Who is the great Intelligence?
The great intelligence is an enemy of the doctor from the second Doctor era. He is first seen in "the abominable snowmen". He controls the Yeti's that we had rumoured would be returning in 2011 (maybe the snowmen were what the rumours were meaning). The great intellegence has no physical body and possess bodies or entities in order to interact with the world around it.
Could sir ian McKellen who is voicing the snowmen actually be the voice of the great intelligence? We have seen in promotional photos Richard E grant's Dr Simeon unconcious (maybe even dead) on the ground next to the giant snow globe the Doctor is talking to. Maybe the great intelligence takes over Richard E Grant's body, especially with Richard E grant returning in the 7b finale.
Possible links to Clara/Oswin?
Now this is purely speculation and theory based on my part. As we know from previous spoilers and set reports it is looking likely Jenna-Louise Coleman is playing 3 different characters. Oswin, Clara and we are assuming again a present day version of Clara. Each of which have no recollection of the previous. The Great intellegence may have a part to play in all of these versions of Clara.
The Great Intelligence travels usinh astral projection. Astral Projection is when the soul leaves the body and travels to somewhere else. What if somehow this is the cause of multiple Clara's through time. When she dies her soul travels to another body/host. We know from set pics reported by RyanFarrr here the Doctor says he is off to find Clara. Could this be a reference to her spirit. We also know from set pictures and reports from the first episode of 7b here that she is unaware to who the Doctor is but the Doctor references Clara from the Christmas special.
What are your thoughts? Sound off in the comments below