This could shake up the HA scene a lot.
I agree. As entrenched as Google is in the daily lives of many of us, an HA play by them could be a rich user experience, albeit even more invasive.
albeit even more invasive.
That could be the interesting part. How much of your HA would they have access too and use? I certainly don’t want to +1 every time I leave the house after all! 
Oooh wow. LOL on the +1
Could you envision Google becoming a part of The Allseen Alliance as part of their IoT aspirations? No so sure.
https://allseenalliance.org/
Imagine Google Now for your home. The thought has me really excited.
I will immediately remove/install anything required to have a Google automated home. The data Google collects is only being used to enrich my life in ways that were not possible just a few years ago. Apple has been collecting iBeacon data, NSA, etc. Privacy is dead unless you live in a cabin in Idaho with no power. But drones will be flying over this area soon.
If a bad guy is smart enough to figure out when I’m home/not home…he will have other boobytraps waiting for his arrival 
I REALLY hope Google buys SmartThings!!!