The U.S. electricity grid largely hasn't changed in a century. But as more and more customers adopt rooftop solar, smart thermostats, electric vehicles, and other technologies, the need to change becomes more and more urgent. Distributed energy resources like these can make the grid more affordable, enhance reliability and resilience, and drastically decrease carbon emissions.
(1) - http://www.epri.com/Our-Work/Pages/Integrated-Grid.aspx
(2) - http://sbrhm.blogspot.com/2011/04/power-lines.html