Right now they are getting their intended result from people in the USA. If Kansas City can have gigabit internet for a low price why can't I? The consumers then will pressure their provider to do the same. However it is not as easy for every other telco.
1. They need to be profitable. 2. They cannot cherry pick areas with high density yet low costs of rollout/living like KC and Austin.
So I do not think Google will ever do this nationwide as it is a bad business to be in with enormous red tape, capital expenditures and geographic distribution. It is a smart move on their behalf to do this but people should not get their hopes up for a nationwide distribution, it will never happen.