Valve's Steam Machine is a revolutionary hardware that aims to combine the best of both PC and console platforms into one machine. Steam Machines will be using a new input device called the Steam Controller.
Steam Controller prototype
Here's the Steam Box Controller Demonstation:
With the aim of having the entire Steam library playable on this new platform, players will be able to play Dota 2 using the Steam Controller.
You can buy Steam Machines by 2014 (Valve time).