An administrator on the Starbreeze forum have confirmed that The Chronicles of Riddick: Dark Athena is "just about done" and is looking for a publisher. Regarding The Darkness 2, the administrator replied with a "unlikely" to happen statement. These are his exact words:
"Yup, Project Redlime is in production. That is all we can say.
As for Darkness 2, it's not impossible but quite unlikely.
Dark Athena is just about done. And the big boys are deciding who is going to publish it.
That is all we can say for now :)"