number 5 of DS's 10 teasers said a very big question about regeneration is finally answered.

I think i missed it as people were talking around me while I watched (very frustrating)

Please can someone fill me in. Please

it's that time lords can change sex when they regenerate, the doctor mentioned in briefly at the beginning.

oh wow! thank you!!

but i don't like that!! I don't want the Doctor to be a girl

The Doctor is/was not the only Time Lord.

So wait The Master was actually The Rani who is in fact River Song, so is human?

But what if River is the Tardis?

And Sally Sparrow too (joke)

she can't be, as then she could not exist across all space and time - basically TDW has said that no TARDIS can take on human form...