A clip from Death of the Doctor was shown on CBBC, see it here.
Russell T. Davies has been interviewed over Jo Grant's appearance in SJA 4
We talked about it a lot beforehand,” says Davies. “I know there’s a feeling that she’d have got divorced, and there was a theory that she’d be living on her own in Wales in a little cottage – some of the novels did this – and you think, ‘Nice idea, but actually that’s absolutely betraying the way we left her’.
We left her with the promise of happiness, of adventure, of love and joy, and you can’t be cynical and undercut that by saying, ‘Oh, she’s a drug addict now! Her husband left her, she’s lonely, her life is bitter’. That’s just interfering with classic Doctor Who and rewriting what we were promised. So I was absolutely strict about that.