This deck contains all the important information about the Gamepad API you will need: current specification status, simple demo, browser support, best devices to use, the implementation part walking you through the JavaScript source code, case study of the game Hungry Fridge showcasing the use of the API, Web APIs in general and different cases for the Gamepad API in the future.
You can run the deck by launching the index.html file in your browser. Bonus points for controlling the slides with the gamepad - I was doing exactly that with my wireless XBox 360 controller on Mac OS X using Firefox browser by pressing A and B buttons to go forth and back through the slides.
You can also go back to the Content Kit's index page.