I don't have strong feelings one way or another. Man or woman, the Doctor could be characterised to be consistent with the previous doctors irrelevant of gender - and with Steven Moffat directing and writing lots of things, I think he could really pull it off in quite a spectacular way.
That said, I don't think changing the direction of a show to make a political point is ever really a good thing. (Unless the show is fundamentally racist, sexist or generally broken anyway - which Dr Who isn't; there are strong female characters and strong male characters both. Torchwood manages that quite nicely as well, having a good balance characters that transcend gender stereotypes; Ianto makes the tea while Gwen kicks arse.) If Moffat and the other people in charge of the show made that choice independent of external pressure, then I'd have no problem with it. I do agree that artistically a spurious change for no real reason other than wanting a token woman doctor would be a bad thing; if anything it's actually counter-productive for the achieving of gender equality.
On a separate note, would the anti-feminists in this thread like to qualify their arguments a little instead of spewing bile all over the place? One of the more amusing and painfully idiotic comments that seems to have sprung up here and there is when people cry 'It's DOCTOR Who not NURSE WHO!'. So women in the medical profession are only ever nurses, then? I'll take it Martha Jones doesn't exist then. Or indeed that male nurses are a hideous joke. just goes on a basic, herd-like utilitarian principle with none of the self-awareness. The people that want a female Doctor are campaigning exactly because of ideas like these and the fact that people feel that these viewpoints are somehow valid or acceptable. But because of the fact that they're part of public consciousness and socially endorsed stereotypes, no-one challenges them.
Also, feminazis? I never knew that feminism had anything to do with goose-stepping, jackboots and anti-semitism. I misguidedly thought that it was about searching for gender equality by dealing with issues that concern the oppression of both genders. But, what do I know?