Definately not. I didn't think he even liked Doctor Who, despite Lalla's (and Douglas Adams') association with it.

Is it bad that I'm still hoping for a fourth series even though we've been virtually told it's definately not happening?

Ooooh Sarah Jane would be good too! I'm not sure if they would do her one now though, considering there's SJA (I know it's New Who Era but still) and her association with New Who. I do know that they said somewhere (I think on the Big Finish website) that they are repeating a companion, hence my hope for Leela!