The show airs Sunday August 4th at 7pm London time, 11am on the North American west coast and 2pm east coast. Hope is that BBC America will simulcast the show to be presented by Zoe Ball in front of a live audience and featuring a selection of past companions and Doctors, including Matt Smith.
British betting agents are favoring Peter Capaldi, who previously appeared in season four's The Fires of Pompeii and Torchwood: Children of Earth.
A check of BBC's own TV listing still shows that a re-broadcst of quiz show, Celebrity Mastermind is scheduled. I have my doubts about such a revelation this early in the year.
[7:20pm UPDATE] Just discovered this advertising video on David Tennant's Blog. They claim Steven Moffat and celebrity fans will be on the show as well
With speculation about who might land Doctor Who's lead role at fever pitch, Zoe Ball hosts a live, action-packed celebration in which all will be revealed, in the company of former cast members and celebrity fans. The current Doctor, Matt Smith, reflects on his time-travelling highlights and has a few words of wisdom for his mystery successor, who will be talking to Zoe, live.
The show is listed as a 30 minute program.