Smartgrid has been in the works for decades. I saw it the subject of debate at conferences in 2004. There are fundimental issues, cultural issues. All those batteries in EVs are not an option. People with EVs simply do not want to discharge them back onto the grid. Firstly, they want to have their car fully charged if they need it unexpectedly. Secondly, they will not accept the diminished battery life associated with extra chrage/discharge cycles.

If we need distributed batteries, dont look to the lightweight and highly specialized batteries of EVs. Oldschool lead acid batteries are far cheaper, last longer, and are easily recycled. That is the way to build out a distributed battery grid.