Anyone else watch Doctor Who? I still do most weeks, for that feeling of family entertainment. And like the old series, there's usually a few clues about plotlines built in.
The early reappearance of Rose "she will return" including the somewhat superfluous soothsaying, the reference to "something on your back" (Monkey? invisible spider? mind controller? guilt of betraying the Doctor later in series?) when talking to Catherine Tate and the subtle use of the so called Doomsday tune to herald, perhaps, the demise of Tennant by the end of this series, or even before the end so that Rose and co can go find him.
My guess is that they'll do a temporary substituion of a female Doctor (Jennifer Saunders) before bringing in the next replacement
The old rashbre central campaign site from 2005 sits forlornly recommending Dylan Moran and, hey, maybe Fran as the sidekick, but I'm beginning to wonder if the controllers have ever read it. They should. DMFDW.
And, of course, we should use an old Doctor Who as a new Master somewhere along the way.