Rumored Steam Controller Design Change
An updated image of the Steam Controller was found by Steam Database in the latest Steam client beta and it carries a significant new feature, an analog stick. The analog stick replaces the left side buttons and is found on the left side of the controller, a look comparable to many available game controllers. PC Gamer Editor-in-chief Evan Lahti commented on the Steam Controller design available at GDC 2014 saying that he "didn’t once feel comfortable, in control, or that Valve’s hardware configuration was in any way an upgrade over a controller with analog sticks."
Source: PC Gamer