I've had a bit of a mixed reaction with my Steam Controller experience. I find the trackpad approach innovative, and the configuration options have incredible depth, but that depth also creates complexity and a steep learning curve. I think it can be a viable replacement for controllers in certain genres, and it can make other genres "couch" viable which previously weren't (turned-based mouse-driven games, for instance).

I think it will find its own niche, overlapping some of the games which were previously keyboard/mouse exclusive as well as some of the games previously XBox/DualShock controller exclusive.

Although I agree that the steam controller will make previously mouse/kb only games viable on the desktop and was probably designed for that, I've been surprised by how much more pleasant it has made gaming with games designed for a traditional controller.

For example, Dishonored plays fantastically well with the steam controller. You have all the advantages of a traditional controller, except the camera control is much more precise and mouse-like.

And although the steam controller may never compete with a mouse and keyboard for games like CS:GO, r/SteamController is reporting encouraging findings, with people claiming to be surprisingly competitive using a steam controller by utilising dual aiming (trackpad for large, coarse movements and gyro for tiny correctional movements).

The bottom line is that for me a steam controller is a massive improvement over a traditional controller, it is like it takes the best aspects of mouse+kb and game controllers and combines them in one package.

Console makers should take note, but unfortunately at this point outside nintendo the traditional console makers are very unwilling to innovate with the base controller.