The way I see it, the Rani is just Lynda Day as an amoral Time Lady. Ifthe Moff won't give us a PG reunion, he can give us Julia as Lynda as the Rani :P.

I could see her as another incarnation of Romana though.

Hmm... there was talk of Gillian Anderson as the Rani. But I don't think she's a good follower for Kate O'Mara. Gillian just hasn't got... how can I put this... the elegance of Kate/Rani. She's a bit to Scully-ish :P.