Can someone explain to me WTF is the Steam Machine controller?

[arcelonious]

Mythmaker1 said:

arcelonious said:

One of the major aspects of this gamepad that has me intrigued is its ability to present itself as a keyboard and mouse (its legacy mode), effectively enabling people to use the gamepad on existing games that weren't designed with the Steam gamepad in mind. Not only is this great for being able to play past games, it's also a great option for games that don't have native gamepad support (where users traditionally have had to utilize third-party software in order to play with a gamepad).

That's one thing I'm really happy to see. I like being able to sit on the couch and play, and it's a pain to do with a keyboard and mouse.

I think that is essentially the attraction for this gamepad, as an alternative (and not so much a replacement) to the keyboard and mouse for PC gaming.  I'll still prefer to use an arcade stick for fighting games, or a wheel for racing games, or a mouse and keyboard for competitive online FPS play, but when I want to kick back on a couch and play most other types of PC-oriented games, I can see potential in this gamepad.