I dot expect google fiber to be rolled out except I'm 6-10 cities or so. And those will probably be smaller metros where penetration will be easier both physically and politically.
Google doesn't want to be an ISP. They want to embarrass existing ISP's in to offering better service, especially in rural areas so that more people can take advantage of Googles services so Google can make more money from advertising. Now, if the giant telcos dont respond and continue to sit on their hands, which is still likely, then maybe we'll see wider implementation of Google Fiber.