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.