Batteries, Ultra Capacitors, and Natural Gas

What are your ideas on the Chevy Volt concept. This car which "may" be available in 2010 will use batteries to power electric motors and have a small gas engine to charge them. It can also be plugged in to recharge. The car is suppose to be able to go 40 miles on one charge or 40 miles before the engine starts to charge the batteries.

I think now is the time to phase out the internal cumbustion engine as the main power source for autos. Batteries or ultra capacitors should be used to run electric motors with small engines only used to charge the power supplies. These engines could run on natural gas as well as gasoline.

The United States has as much natural gas as Saudi Arabia has oil. Until hydrogen becomes practical, LNG could be used.

What are your thoughts???