Danny Hargreaves, the SFX supervisor and technician, reported on twitter today that filming for the 50th Anniversary has finished:

He reported that, "That’s a wrap ! Dr who 50th Done !! Wow it’s going to be epic !!!!!!!!!"

We've seen several bits of filming, notably Coal Hill School, Tennant, and a Zygon, but we also know there's been a lot of work done on private property and in studio. Who else might be returning?