Mr Light wrote:
Do we know what Pertwee serial airs and when yet?
This is my own theory, which could admittedly be full of hot air. At anyrate, I think the pick for the Pertwee serial will be meaningful in terms of whether we'll get a multi-Doctor anniversary special.
If they pick The Three Doctors, it's to set the stage for newbies about the idea of multiple Doctors.
However, if they don't pick The Three Doctors, it's because they don't want people to expect a multi-Doctor anniversary special.
So, depending on the anniversary plans, I'm thinking it's either The Three Doctors or Terror of the Autons.
Terror fits well because its 4 episodes, introduces the Master, and showcases UNIT. It's a good way to showcase that particular era.