I'm watching it with great interest, but I was less impressed. The games they were playing were all older games, and I kept thinking how much better it would have been with a keyboard and mouse.
But if games are designed with the new controllers in mind, it could be quite good.
However, I'm kind of opposed to game controllers on principle. If I was a teenager, I might not have this issue, but I can't see owning a device just for controlling games, when I can have such fine control with a mouse and keyboard (which is already on my desk). I have no such compunction about buying a $250 video card that is only really necessary for the games I play, but I never said I was consistent.
I don't like consoles. Don't like console games or what consoles have done to gaming. Don't like third-person cover-based shooters. Feels like I'm in a firefight with a marionette with strings with too much slack.
Plus, I don't play games in the living room. Having said all that, I like the looks of the Steam Box, and the fact that it's something anybody can build and runs Linux. I like that Valve is releasing the CAD files for the box so you can even build one that looks like the one Valve is going to sell. It shows their commitment is to gaming instead of trying to be some kind of all-in-one social shopping device that will report back to HQ with details about me.
I like the idea of a company trying to do what it does instead of making everything a hook into something else, like Sony, Microsoft and to a lesser extent, Nintendo. The ultimate end game of that strategy is iOS, which is in my eyes an abomination.