The developer that made this no longer exists, although I suppose Bethesda could look for a new studio to make a CoC game.
The Developer Document for the sequel to DCOTE is still floating around "here and there", I'd be happy to provide it if Bethesda wants to work with a studio on producing a sequel, however as sad as it may seem, I feel it is unlikely to come. Nowadays there is just too great a demand for games about futuristic space marine combat scenarios and US military modern warfare. It's a shame too, as even playing it now, I feel Dark Corners of the Earth is the most immersive game I have ever played. It really does take you by the gaming wrists and svck you in to the point where you almost forget you're sitting in a computer chair playing it all.