The day has come where you can not ask Google to trigger some sort of action in your home.
It starts with Google's acquisition of Nest, where now you can control the temperature in your home by saying, "Okay Google. set Nest to 73 degrees."
It also can work based on detecting when you leave work to come home. See workswithnest.google.com.
Yes, Google will take that data from Google Search/Google Now and pass it through to their Nest division to change the temperature in your home.
This is the start of a huge change in how Google and search works.
From the predictive search of Google Now, all the way to the implicit home automation of what you want to expect in the future.
This is really really big, it is hard to even explain how big this is. Google reads your email, knows you have a business meeting in the UK, already shows you flights you can book via Google Now and says, do you want to book them? It books them when you say yes and then figures out things from there.
It is your personal assistant but actually takes the actions for you. Before it just gave you hints but now, it is doing the actual task for you. Real task completion.
Scary, yes - useful and wow, indeed.
