With Google's track record of jumping into a market and after they have millions of users shutting it down, I'm surprised they didn't do this years ago.
How long before Honeywell does the same? The company spun off their residential services division (including thermostats) about 7 years ago and at first things were fine, but in the last couple of years the service has become increasingly unreliable. Their servers have gone down quite a few times and settings changes are sometimes delayed even when the servers are up.
Their Z-Wave thermostat is a nice upgrade without concerns about someone sitting in a corporate America e-suite deciding to pull the plug.