Nope, it's nothing to do with the comedy glam-rock band. The Darkness** that's currently being developed at Mandeville pictures is an adaptation of the supernatural gangster comics by Garth Ennis, Marc Silvestri and David Wohl.
The creator-owned series began in 1996 at Silvestri's own Top Cow comics company, and involves a mobster who develops the useful ability to summon demonic creatures from another realm (luckily he hasn't so far come up with any crimson-faced puppeteers who like Tiny Tim records). The drama comes from Jackie Estacado's struggle to control the creatures he's unleashing, while taking on his enemies in the world of organised crime.
There have been attempts to get a Darkness film going in the past - once by Scott Stuber and another time by the Weinsteins - but the only adaptation we've seen to date is a videogame. Mandeville already have a creative relationship with Top Cow though, with movies based on Alibi and Crosshair also in the works. They must all be hoping that three's the charm.
We're just at the development stage at the moment, so it'll be some while before The Darkness sees production. In the meantime, Ennis' own short film Stitched will make its debut at Comic Con.