After the disappointing 'Planet of the Dead', Doctor Who has managed to come back to the realm of Good Television. 'The Waters of Mars' wasn't scary, Doctor Who hardly ever is, but it had a darkness to it that's sometimes missing. The Doctor meets a group of people who are 'definitely going to die', and for once he believes that he shouldn't help them. As the ending approached there was a strong sense of doom, even if they were just running away from water. I've always imagined that the Doctor's character was pretty rigid, but by the end he seemed to have undergone a massive change. They were even playing ominous music over his dialogue.
It's all building up to a Christmas special that's already looking better than usual (Cybermen bore me, sorry). And then on to Steven Moffat's reign. It may be unrealistic to expect every episode to be as good as 'The Girl in the Fireplace', but its good to have dreams.