The problem with electric cars isn't the vehicles themselves, its the infrastructure. To accommodate for an increased demand of electricity, we would have to build new & upgrade the electrical infrastructure; that will cost a lot money. If we really want to make an impact, we have to change the power plants since they account for a huge percentage of CO2 emissions; that too will cost a lot of money.
We need proper infrastructure in order for cars like the Chevy Volt to take off. Billions of dollars will have to be spent to upgrade the grid. It will be several years before we see charging stations everywhere.