The Steam Controller has been finalized, it's coming out later this year, and it's now up for preorder (for $49.99). Now, you can watch the above video for a slick and bite-sized demonstration of what Valve's official game pad is all about.
Since its official announcement almost two years ago, the controller has been an object of immense interest in the developer community -- as the company has since gone on to both demonstrate and iterate on it since then.
If you're curious to find out how far the device has come, don't miss Tommy Refenes' (Super Meat Boy) impressions of the circa-2013 version of the Steam Controller.