The expansion to Huntsville may seem odd at first blush when Google Fiber has focused on either large cities or smaller towns with ready-to-go networks. A burg with roughly 180,000 people isn't exactly a lucrative market. However, Google sees this more as a proof of concept for gigabit internet than anything else. Huntsville has an extremely high concentration of engineers and scientists thanks to its biotech and space work -- it could really use those breakneck speeds to shuffle large amounts of technical data.

Also, the use of a city-run network shows that Google is more flexible on its rollout than you might have thought before. It would rather give up control of the fiber cables than risk missing out on a chance to expand its reach. It's doubtful that Google Fiber will become ubiquitous any time soon, but you could see it become a relatively commonplace option in those towns where gigabit-class municipal broadband exists.