Great for competition now, sure, but once copper and coax become obsolete Google becomes the new incumbent monopoly. How is that good for anyone?
I'm not saying it would be easy. It would take a lot of legal work. But if google's missions to not be evil, and disrupt the ISP market are to believed, they could make it easier.
Incumbent broadband providers are upgrading offerings in response to Google, so that doesn't seem like a particularly obvious end result.