Here's a quick look at some games being played with the prototype version of the Steam Controller -- the same version that we'll be shipping to 300 Steam users later this year. We'll post more demonstrations like this soon, including footage of some other game developers using the controller to play their own games.
More information can be found right here on TGN (as it's made public) or through the Steam Universe community page from the Steam Community.
However, most games require keyboard inputs which would likely take up one trackpad, so I'm wondering how a controller user would fare against a keyboard/mouse user? I've played first-person shooters that require chasing an enemy down my sights (like say sniping a moving target that I failed to anticipate for), and that requires moving the mouse in large distances. From what I'm seeing (especially in the Civ 5 demo), I would need several swipes to do so, which makes twitch gaming a bit more difficult (though easier compared to thumbstick controlling). But again, I don't know for sure until they announce what the range limits are.
Also wondering what the battery life of the control would be when it becomes developed enough to go wireless? Relying on force feedback at all times to know where the buttons are seems like a good way to drain batteries and decrease the life expectancy of the controller through increased wear and tear.
Would be cool to see this design win the next Emmy award by The National Academy of Television Arts & Sciences though.