From ShadowLocked.com, there is a 42 min interview with the Seventh Doctor, Sylvester McCoy, and Ace, Sophie Aldred. At 21:30 Sophie starts to discuss David Tennant and Tree Fu Tom, the new animated series produced for UK children's channel CBeebies. Sophie is Tom in the cartoon and David Tennant plays Twigs, an Acorn sprite. As she states in the clip, this isn't the first time she has worked with David Tennant: their first meeting was on CD for a Doctor Who spinoff.  She has great praise for charisma, his acting and for Much Ado About Nothing. Sophie gives a few spoilers and hints about Tree Fu Tom. Evidently, David Tennant is the funny character and the pair make up a bit of a double act. Sylvester McCoy spends several minutes discussing Scottish accents, rolling R's, David Tennant and a bit of Rose. 

The whole interview is great! Do listen to the full 42 but and remember that the interview is in aid of raising money for a Shadowlocked's favourite Doctor Who spin-off The Minister of Chance, starring Julian Wadham, Sylvester McCoy, Jenny Agutter and Paul McGann.  Visit IndieGoGo to donate to this free Doctor Who spin off.