You know what I want to happen for the 50th anniversary?

After the episode, they just have an hour long non-cannon just-for-fun episode

In which they get all the actors who have played the Doctor, a companion, or any other major character

Drop them all in a gigantic TARDIS set

Tell them not to break character

And just see what happens.

Doctor Whose Line Is It Anyway

Where time is wibbly-wobbly because the points are non-linear.