Barrowman is still persona non grata and it's doubtful if fandom would accept Torchwood without Cpt Jack. Maybe after Rogue is finally revealed to be Jack.
I'm not particularly hopeful for another Doctor Who spinoff. Torchwood was magical, but second and third sci-fi shows under the same intellectual property are usually bad.
All that said, I think the Terileptils (or are we getting the sea devils, I havent been paying attention...either way, both are awesome) and I look forward to seeing more of the overly dramatic campy goodness.