Why was I under the impression that Time Lord sex is fixed, while physical species traits are not? I thought there was canonical justification for no female Doctor (not due to sexuality, but rather physical sex).
"Three eyes, no eyes, no head..." or something to that effect (I'm pretty sure about the no head thing) during a new Who regen scene. That suggests an awful lot of flexibility.
Indeed, but it's been hinted a great deal that the Doctor remains fixedly male when taking human form. The consistent use of the pronoun 'he' being one. Not to say that the writers can't deal with that issue in order to allow for a female regeneration, just that the very little we know of Time Lord regeneration actually suggests it isn't a flexible as the Doctor's statements might have us believe. Consider that the Doctor continuously ends up visually human after 12 regeneration cycles, despite his constant exclamations about 'what do I look like am I purple etc.'
It can be dealt with, but this is one situation where I see some continuity along the lines of physical sex being beneficial. We already know the Doctor is not heterosexual; I think invoking a female Doctor might actually dilute that rather groundbreaking revelation.
