We’ve known the the Steam Controller will see quite a bit of change thanks to an interview with a controller product designer during CES 2014 – but the Steam Dev Days has revealed a bit more about the impending changes.
Twitter user @DaveOshry notes with the hashtag Steam Dev Days that beta testing has proven successful allowing the Valve team to head back to the war room for more redesigns: "The Steam controller will see more changes before it goes on sale. They’ve gotten tons of feedback from the beta."
Various other Tweeters have also stated that Valve is actually getting rid of the touchscreen and replacing with physical buttons for retail versions. Twitter user @omglazerkittens says, "They are experimenting with analog rather than track pads."
On the developer side of things, the controller API will also support up to 16 players at once.