From the front page of HEXUS.gaming :
Check out the full story at HEXUS.gaming .Sin Episodes, the sequel to Ritual Entertainment’s much vaunted FPS is on the way and coming to your PC down the wire through Steam. If proof were ever needed that time heals all wounds, Valve and Ritual, once arguably rivals with Sin and Half Life, have now teamed up for online delivery of Sin Episodes....
...What is really making Sin Episodes unique is that, given the association with Valve and as the name suggests, it will be delivered in episodes via Valve’s Steam content delivery system. The plan is that an episode will be released every three to four months at a cost of roughly US$20 per episode. Just how much content is in each episode is unclear at this time but what is known is that players actions in previous episodes will have an impact in what they see in the next.