Big Finish were a prominent presence at the Cult Expo Publishers event, at the Cinema Museum in London on Saturday 13 October. Guests included Paul Darrow (pictured) and Jacqueline Pearce, both famous for roles (as Avon and Servalan) in Blake's 7 - but also guests stars in sixth Doctor stories in 1985 (Darrow in Timelash, Pearce in The Two Doctors).
At a panel of Big Finish writers and producers held as part of Cult Expo, Marc Platt (writer of classic Who story Ghost Light) hinted that he has been asked to contribute to the plans for the programme's 50th anniversary in 2013. Platt's Big Finish audio Spare Parts was the inspiration for the 10th Doctor two-parter Rise of the Cybermen / The Age of Steel. However, like other writers for the 1963-1989 incarnation of the programme, he has not yet written a script specifically for production in the post-2005 version. Judging from his answers to other questions, though, whatever Platt may be writing, it won't be a TV version of his Virgin New Adventures novel Lungbarrow, which delves into the Doctor's origins on Gallifrey and introduces 44 of his cousins...
UPDATE (16 October 2012): Marc Platt has asked us to clarify that his comment referred to ideas for Big Finish's output in 2013 - not the BBC TV series. Thanks to Marc for contacting us with the clarification.