No, those who care about service will switch to google fiber. Then Comcast will see that the number of complaints about their service is decreasing, and go on to praise their employees.
For now companies which should be scared of Google Fiber aren't. It took the US years and lot of tax money to build the infrastructure which current ISPs own. Google has done parts of one city with only 2 more on the way. It will take a long time until their business practices cause them failure against fiber competitors. ISPs aren't interested in improving their networks, only in making money off of the money they've invested into at this point.