This post is specifically for our German users as Google Home is about to be launched in Germany tomorrow - but everyone in the US who already owns a Google Home might be interested as well:
Since today, the openHAB 2.2.0-SNAPSHOT distro is able to integrate with Google Home. This is done the same way as for Amazon Echo (without using the skill), i.e. by the Hue Emulation add-on, which makes openHAB expose arbitrary items as lights by mimicking a Philips hue bridge. Kudos to @digitaldan who made the necessary changes to that add-on, so that Google Home correctly recognises openHAB as a Hue bridge.
There is one caveat, though: Google Home does not listen to the port it is told, but always expects the hue bridge to be available on port 80 - this means that you have to configure openHAB to use port 80 instead of 8080 for the webserver (check the docs on how to do that) and for using port 80, you need to make sure to run it as root.
If you want to see it in action, check out this video on YouTube (sorry, it is one of the rare ones that I did in German).
I hope you like it!
P.S.: There is also work underway to have an official openHAB Action for Google Home, but this might still take a while - if you are interested, follow the linked topic for updates.