No one knows yet for sure about the John Hurt Doctor, but it's very likely that he's a secret past version of the Doctor, not a future version. There's a reason for that, as part of the episode, but I won't spoil it.

As for the Timelord gender thing, in The Doctor's Wife, in season six, it was mentioned that a Timelord called Corsair changed genders during a regeneration. So it's something they could do if they wanted to. But as much as there's a male demographic that watches the show for the cute female companions, there's also a very real female demographic that watches the show for the charming Doctor, especially since Tennant. So it would be a risk to make the Doctor female. She'd have to get a male companion at the very least. Since Clara has previously confirmed that she's coming back for the next season, I have to feel they'll go with a male Doctor again.

But you never know. A female Doctor could certainly be interesting. I'd actually kind of love if they turned Clara into the Doctor (again, no spoilers, but it wouldn't be impossible with some hand-waving), and then wrote her like they did for her first two appearances (Asylum of the Daleks and The Snowmen, where she was quick-talking and clever).