Via AnandTech and sourced by Valve itself, it's now clear that the Steam Machines are not for this year. Valve is officially pushing back the release apparently due to the design and re-design of the controller. In a statement made to the Steam Community, Valve explains the controller is undergoing a lot of changes and improvements as the feedback from industry and die-hard gaming community flows through to the engineers.
The Steam Machine was one of the major hypes of the past six months and the entire PC component industry were eager to jump on board. To see what the Steam Machine can really do in the living room, we'll have to wait another couple of months.