Rucka was on the Word Balloon podcast and confirmed that Diana's Daughter is indefinitely shelved, said he just couldn't get the story to work. He said it's possible that he'll figure it out one day and then circle back to DC to see if they still want to do it but as of now it's not happening.
Huh. I'm a little surprised that a writer of Rucka's experience pitched the idea in the first place then.
«Speaking generally, it is because of the desire of the tragic poets for the marvellous that so varied and inconsistent an account of Medea has been given out» (Diodorus Siculus, The Library of History [4.56.1])