Riccardo Signorelli and others at MIT are developing a capacitor that will be able to replace batteries. They use nanotubes of carbon to drastically increase the surface area in the capacitor. They say it will take 5 years to get it to market, but Ford and MIT are working on this together, and I doubt that Ford wants to see electric cars really take off. I hope this doesn't just disappear. MIT recently wrote a report that Gas cars are going to be the only used option by the masses for decades to come.
Did you know that electric motors can run for over a million miles, and the cars never need an oil change? The capacitors will be able to recharge over 300,000 times, and in just a few minutes, if they would build electric "gas stations" that could put thousands of amps into the capacitor bank. Do a search for "Carbon Nanotube Enhanced Double Layer Capacitor" if you want to read more about it.
-Paul
