Loved it! Can't wait now.
I have a feeling that this other "Doctor" is... I don't know, an actor. You know, like he's part of a little fan group like LINDA, only... Victorian. Have a good look at that sonic screwdriver.
It's like he's doing an impression of Ten, but he's never seen him, only heard about him - so he just knows vaguely about the clothes and general mannerisms, and all the Time Lord stuff.
So, I don't think he's the Doctor. But I wouldn't mind if he was.
(Also - Rosita??)