Fadell led the team at Apple that created the first 18 generations of the iPod and the first three generations of the iPhone. Google of course is now in the device business via its Nexus smartphones and tablets as well as its ownership of Motorola.
It's logical to assume the addition of Nest also means Google hopes to plug smart homes together with Android devices, and its developer ecosystem.
In a blog post Fadell said in part:
"Google will help us fully realize our vision of the conscious home and allow us to change the world faster than we ever could if we continued to go it alone. We’ve had great momentum, but this is a rocket ship.
"Google has the business resources, global scale and platform reach to accelerate Nest growth across hardware, software and services for the home globally. And our company visions are well aligned – we both believe in letting technology do the hard work behind the scenes so people can get on with the things that matter in life. Google is committed to helping Nest make a difference and together, we can help save more energy and keep people safe in their homes."