It was originally announded at being published by Image Comics in September, through three solicitation months have passed since then, without sign.
The new issue of Supercrooks from Marvel, published tomorrow, has three pages of previews (one of which is reproduced below) and a couple of head sketches of characters from the planned twelve issue series, Jupiter's Children. And a date for publication of Spring 2013 – which would handily be around the time of Kapow 2013.
I was told last week that Quitely was still hard at work on Pax Americana for DC Comics, which may explain the delay.
And while this page shows the classic quitely, bouncy three dimensionally formed bodies, with seam-conscious clothing, other panels in the preview indicate a looser, Hugo Pratt/Joe Kubert approach, with specific areas chosen for detail, such as this: