"I am aware that Helen Mirren has stated it is time a woman was cast, well all I can say to her is i think it's about time we let a man play The Queen!" - steven moffat (Doctor Who writer and producer)

The cry for a female Doctor is odd, Why should one character be singled out as having to represent all interested groups. There are thousands of hours of TV made every week around the world and I'm all for a better representation of the majority of humanity that are not white, english speaking males but I'd like to see it accros the whole spectrum and not with black or female versions of old characters but new interesting characters that are true to the experiences of real people.

Having said that if there was a narrative/haracter driven reason for a female doctor or green doctor or child doctor or wheelchair-bound doctor then bring it on.