Back when Prey was canceled, I imagined for myself that a part of the reason they gave up the project (in addition to technical problems) is that Half-Life had just come out. There they were, having aimed for the sky and talked for years about bringing story and real charachters into the shooter genre, and then HL came, and they realized that they just did not have the better game. So they decided to start afresh.
Is there a smell of fear 3dRealms officies today? All this work to make the "next" game, and now Valve has made this game again, and will release it just before them.