According to posts on the Restoration Team forum the BBC’s in-house magazine Ariel has published details on the long rumoured Sarah Jane Smith spin-off.
The magazine says:
“CBBC is developing a spin-off series from Doctor Who based on the adventures of investigative journalist Sarah Jane, played by Elisabeth Sladen, and to be written by Russell T Davies.
Sladen, who originally played the Doctor’s assistant in 1973, returned for the last series where she was seen vying with young Rose Tyler for the Doctor’s affections”.
There is currently no official press announcement or statement on this development.