The Official BBC site have released details of who will be at the Doctor Who Live: The Next Doctor announcement tonight.
Out of the Doctors, Peter Davison (The Fifth), Matt Smith (The Eleventh) and Colin Baker (The Sixth) will be at the event.
Out of the companions, Bernard Cribbins (Wilfred Mott) will be there. Also included are Anneke Wills (Polly), Katy Manning (Jo Grant), Janet Fielding (Tegan) and Bonnie Langford (Mel) will be there.
Mark Gatiss, a writer and actor for Doctor Who, has provided a recorded video to be shown there.
"Celebrities" in the studio will include Rufus Hound, Liza Tarbuck and from Outnumbered, Daniel Roche. There’ll also be video contributions from Professor Robert Winston, Jo Whiley, Bruno Tonioli and following his appearance in The Power of Three, Professor Brian Cox.
What's the most puzzling is how many of these people will be live in the studio or via the internet or via pre-recorded material. And where is Steven Moffat, as previous announced?