The purpose of the Steam Controller, which is to be released along with the upcoming Steam Machine console-like PCs for the living room, is to merge the precision of a computer mouse with the comfort of a handheld controller. The goal is thus to offer the best of both world and to achieve this developer Valve has created a controller with to touch sensitive circular pads where the analog sticks on more traditional controllers are placed.
However, it would appear as if Valve intend to offer a standard option along with these touch pads. Why? Because SteamDB recently posted an image on Twitter showing a new Steam Controller prototype with an added analog stick.
It's still a prototype and there's no guarantee this will be the final design, but it points towards a controller with both cutting edge and more traditional options available. That being said, we hope Valve continue to explore the touch pads and haptics, as that feature is the one separating the Steam Controller from all others on the market.