'I agree. My prediction was that he would be reduced to a voice over a la Charlie Angels or a few small bits in the first eposide or so.'
Yep. RTD tried to sell a Gwen-centric show to the network before (Torchwood was supposed to be Gwen-centric in the beginning) so I'm guessing that Jack will have a little screen time as RTD can get away with.

'But didn't someone (here maybe?) mention a whole new Captain Jack series? Or was that just wishful thinking (or me hallucinating again).'
John has said in an interview that he would love to do a Torchwood series in the past so it was probably wishful thinking based on that.