I'm very impressed with it. Keep in mind that this is still in it's infancy, so I'm focusing more on the potential as opposed to the current content. I think having a second screen such as an iPad, will give the creative types behind these blockbuster triple A games the canvas to come up with some fantastic additions to our favorite games. Beyond that, I like that I am finally able to use the keyboard on my phone and tablet to type on the Xbox. Maybe I'll actually use the Search function on Netflix now...
I don't think SmartGlass is going to change the way we play video games forever, but I can easily see it enhancing it. Can't wait to see how this is used in the future.