Valve announces S.T.A.L.K.E.R.: Clear Sky will be digitally distributed exclusively via Steam worldwide, with the digital release of GSC Game World's first-person shooter prequel to coincide with its appearance on retail shelves. The announcement concludes saying S.T.A.L.K.E.R.: Clear Sky is currently slated for release later this year, so we've asked GSC Game World if this means the game will miss its announced Q1 2008 release date (story), but have not yet received a reply. Valve has put up a S.T.A.L.K.E.R. Clear Sky Product Section on the Steam Website that features some new screenshots.