Doctor Who Am I?
Perhaps it is not so much the search for who the Doctor is, but his acceptance of who he is that will define the current season.
Theres an interesting thread running through the current iteration of Doctor Who. A question that is central to all of us as human (or rather sentient) beings but one that perhaps isnt so easy to answer. What is identity? What makes us recognizable as us? Is it appearance? Is it memory? Is it our actions, our core beliefs? Who are we really? This is a question that the current revival of Doctor Who, especially since series 5 when Stephen Moffat took the reins, has not shied away from. In fact it has been and continues to be explored in depth and in some particularly fascinating and thought provoking ways. One of the central tenets of the Doctor Who universe is that the Doctors identity is itself often in flux. Regeneration doesnt just bring him back to life, it fundamentally changes who he is - his looks, his personality, even his beliefs and his reactions to his environment. What he does retain are his memories. Most of us eventually end up accepting this new aspect as the Doctor. Does that mean his memories define him? Is that what makes him recognizable as the Doctor even when everything else has changed? One could argue that we all regenerate throughout our lives though in a less spectacular way. Certainly Im not the same person at 47 that I was at 22 though my younger and older selves share certain memories and experiences. Is that what connects us to the idea of the Doctor? That perhaps he is more like us than he initially appears? 
The monsters in the Who universe often prey on our fear of loss of identity. In Asylum of the Daleks we witness humans being turned into Dalek drones. These humans, if they can still be called that, are emptied of their personalities and physically altered with Dalek technology. They become a kind of cyborg, but they are not truly half human and half dalek since they are no longer in control of their former human identity. Their memories appear only in service of the Dalek cause and, stripped of their free will, they simply do as they are told. Their identities have been removed and replaced with a set of commands. Interestingly, it is Oswin a human who has been physically converted into what appears to be a full Dalek who retains most of her identity. She remembers who she is and she refuses to be suborned to the Dalek agenda. She actively fights to retain her sense of self and virtually surrounds herself with elements that help define her as a human a taste in music, an interest in food. The Weeping Angels also seem to exist to mess with our sense of who we are. If they dont outright kill you, they send you back in time - back to a place where your memories and experiences are not as valid. You are no longer embedded within the things that have defined you your family ties are severed, the world as you knew it no longer exists. Your modern identity in this new environment becomes a liability, as in order to survive you must change who you are to fit in with the new era. How much does environment impact who we ultimately become? 
One of the themes emerging in series 7 seems to be the idea of memory and the role it plays in forming the Doctors identity. In Asylum of the Daleks, Oswin erases the Doctor and all his exploits from the Dalek path web. They no longer remember him. In Dinosaurs on a Spaceship, Solomons scan returns no information on the Doctors identity or subjective worth. Even the music cues are telling. The Doctor claims to have played the triangle on Bizets Carmen and was the third and fourth hand in Franz Schuberts Fantasia in F Minor for piano four hands. And yet no one knows this but him. He doesnt exist as part of the music in the minds of most citizens of the universe. His reasons for wishing to erase himself from the universal consciousness are understandable. It was explicitly stated in both The Pandorica Opens (Series 5) and Asylum of the Daleks that his enemies have grown stronger in fear of him. But one wonders if this reasoning is ultimately misguided. He may be removing fear but he is also removing hope. And perhaps that is the crux of the Doctors identity. Like most of us he is more than one thing. Perhaps in allowing himself to be defined by outside events he is losing sight of his own sense of who he is. Its an interesting exploration, and one that Stephen Moffat seems to be embracing. 
Its not only the Doctor who is struggling with this but at least one of his companions as well. As she explains in a pivotal scene from Dinosaurs on a Spaceship, Amy cant settle into her own identity without the doctor. He has defined her life for so long, from such a young age, that she doesnt know who she is without him. In God Complex (series 6) the Doctor recognizes this and tries to separate her from her reliance on him. But she is, as of yet, unable to make the leap and feel comfortable with herself as her own being and continues to define herself through her time spent with the Doctor. It is a sign of her growth perhaps that by the end of the episode she has decided to go home and back to her life with Rory rather than continue to follow the Doctor on his latest adventure. Is Amy's struggle a microcosm of the Series 7 arc? I know Stephen Moffat has declared there is no arc but I think perhaps that in reality it is simply a subtler one. Questions of identity are quite complex and tend to shape themselves around whatever situation we are presently in. Any answers we and subsequently the Doctor and Amy arrive at are by their nature subject to change at any moment. Perhaps identity, unlike certain periods of time, cannot be fixed and must be understood and accepted as fluid and adaptable. The Doctor has stated himself that our lives are made up of many things both good and bad. Perhaps it is not so much the search for who the Doctor is, but his acceptance of who he is that will define the current season. I cant wait to find out.