Let's be clear, this is not an announcement of a partnership, simply that the two are in talks to put Waymo tech in Honda vehicles. In a sense, this is an announcement of an announcement. If everything goes through, expect Honda engineers from the US and Japan to work with Waymo teams in Mountain View, California and Novi, Michigan. The stated goal is to integrate fully self-driving sensors, software, and computers into Honda vehicles.
It's obvious the deal isn't exclusive, given the announcement of an FCA partnership mere days ago. Likewise, Honda says in its release that it will continue independent autonomous tech development and use the Waymo partnership to explore various options. The Waymo-equipped Honda vehicles would enter into Waymo's already active fleets in several US cities. If all goes through, expect a final announcement of a partnership sometime soon.