This writer’s hopes that Jenna-Louise Coleman’s character would be a regenerated Susan sadly appear to have been well and truly dashed.
A set report from her debut episode (provided for the Internet by Doctor Who TV) has pointed out that there seems to be more than one Victorian jaunt in the Doctor’s future, which is rare for the show (and when you consider how much effort is needed to build a Victorian atmosphere, it figures that there would be a damn good reason).
Spoilers below (perhaps – remember that we could be completely wrong) on why this could be:
The Doctor’s new companion – widely believed to be called Clara – is speculated to be from the Victorian era (which, to be fair, spans 60 years) and has been sighted in Victorian clothing. Madame Vastra has also been sighted on location more than once.
So, where and when is the Doctor’s new lady-friend from? We can speculate all we like (and this writer’s still hoping for Susan), but the bottom line is that we’ll have to wait until Christmas Day to find out like the rest of you!