Monday at 10AM Pacific Standard Time Valve will update this site with something. From the site it looks like that first circle on the left will become a clickable button.
Current internet speculation is that it might have something to do with Steambox hardware, but I have a feeling that it will be something like Steam Workshop for Big Picture mode, with people able to make updates for games to make them easier to play with a controller and to Big Picture mode itself.
What are your thoughts? Are you excited? Do you have any predictions of your own?