I don't think this is what Google had in mind, but I hope this will become part of their plan:
The real problem with Comcast isn't the connections to the home or to Comcast's servers, it's the routers which move traffic to other networks. Not just their peering relationships, but the hardware they overload along the way.
These devices have a network test function. They provide Google with a whole bunch of edge devices in the consumer Internet space which openly say they're going to communicate with Google. I'm hoping that Google will use these to map out ISP network and use the information to A. spoof DNS results to avoid overloaded equipment, B. Tattle on problems to partners to adjust BGP (or whatever ISPs are using now for routing tables), C. Use the information to bludgeon the ISPs (OK, really that just means Comcast) in the press and in Congress to force change to facilitate faster, cheaper connections.
So they can push more ads.