It's made by Valve. That means I already believe it works better than any other controller in existence.
I'm not that interested in playing pc games on my tv, I like the way I have things set up now. But I could easily see myself using this controller when for certain games instead of the 360 controller I use now.
Valve design has always been top of the class and I believe they must have put a ton of research into getting to this point. So if this is what they're showing us now then it must work beautifully.