I don't think you could do a whole season without the Doctor. People would leave in droves. There is always fanfic though. Get writing!

I have really enjoyed Matt Smith. He has been my favorite Doctor (although I've only seen the modern era).

After a couple of chipper fellows in the role it might be nice to go a bit darker for a while. Not evil Doctor, but a no nonsense guy who laughs at wearing a fez or celery on your lapel. Someone you know is going to win, not because he is the Doctor, but because of that look in his eyes.