This is Google’s way of trying to compete with the Apple TV, it’s a $35 dongle that plugs into your TV through HDMI and basically turns it into a smart TV. It’s a device that works cross platform, from your Android phone to Mac computer, and it will allow you to control it with any device and stream Netflix, Youtube, and more to come with them releasing a SDK alongside it today. Currently it can’t directly compete with Airplay, as it doesn’t let you stream local content from a device or computer and relies on cloud based content, however as opensource as Google is, I suspect someone will develop the ability to basically Airplay to this device. At almost a 1/3 of the price of the Apple TV at $99, this could be very successful and will have to wait and see how developers support it. More info here.
Check out the intro video below: