Mark Gatiss?
(
_Felix 's school of dance and occult sciences,
Tue 20 May 2008, 12:38,
archived)
Steven Moffatt...
and apparently Lord Stephen of Fry was lined up, but he had to drop out
(
Joe Scaramanga with a G-double-O-D vibration,
Tue 20 May 2008, 12:40,
archived)