Nilay Patel, writing for The Verge:
Although Fadell says Nest will remain mostly independent, with its own identity, team, and even offices intact, it will most certainly become a part of Google. "It's somewhere between YouTube and Motorola," Fadell said yesterday, describing two of the search giant's more famous acquisitions. Motorola has remained almost completely independent, "firewalled" away from Google's Android team, while YouTube has become more and more integrated over time — with a recent outpouring of anger when its comment system was tied to the niche Google+ social network.
So what will happen to Nest? Fadell called any speculation "totally premature" yesterday, but that hasn't stopped customers from worrying — and most seem to think Google will "ruin" Nest in a variety of ways, with Google+ integration standing in for a host of potential sins. Others worry that Nest will fall victim to the ongoing platform war against Apple, although Fadell says the company will continue to support iOS.
I’m not really sure where I stand on this—as a Nest owner and Google skeptic (albeit user as well), I want to be concerned, but I also want to wait and see. The problem is that when you’re dealing with the kind of data that Google deals with, by the time you’ve come to a well thought-out decision, it’s already too late.