Apparently you are a thinker...
I applaud your thought into your answer, and not taking the 'knee-jerk' superficial options. The nasty truth, as you so efficiently explained, is since we don't use very much Nuclear, Solar, Wind or even Hydro systems to generate that "Clean Electricity" to use, we rely on nasty old Coal, Oil and natural gas to generate the "Clean Electricity" we are putting into these electric cars. Until we replace all those coal and petroleum power plants with Nuclear, Solar, Wind and Hydro-electric power plants, electricity will be as dirty as gasoline, you just won't see if coming out of the tail-pipe, which I guess if you don't see it, no foul, right?! The most efficient power generation at this time, is nuclear, but then your are left with all that nuclear waste to dispose of!
I recently read about a new sports car that is an electric hybrid - it uses a gasoline engine to recharge the batteries. It has a top speed of 200 mph and gets approximately 200 mpg. It can go from 0 - 60 in 3 seconds! The manufacturer of the car is offering his technology to any automaker that will accept it. Also, a company called EEStor in Ceder Park, Texas has developed an "Ultracapacitor" that carries enough charge to give a automobile a 500 mile range and it can be fully recharged in 5 minute!(http://ohgizmo.com/2006/09/26/eestor-ultracapacitor-5-minutes-to-charge-500-miles-per-charge/)
As for petroleum, according to what I have heard from various reports, the U.S. has some, if not the largest oil reservoirs in the world. The Gulf of Mexico, is considered to be the largest, if what I have read is true, but there also is a enormous deposit under the Rocky mountains, as well as vast amounts trapped inside the oli shales, as well as in Alaska. In fact, we enough petroleum to last us for the next 200 years, unfortunately, EPA and various organization such as Sierra Club, Green Peace and other such groups, lobby hard to keep us dependant upon foreign source of petroleum. The simple fact is this, even if a new, super-duper electric auto came out today, it would be 10 to 15 years in getting everyone switched over, as most folks can't just run out and buy a $20+K auto. So petroleum is going to be around for at least another decade, and I suspect. We have to be very careful not to respond to "Knee-Jerk" decisions and half-baked hype about this alternative fuel or global warming (which is a total farce). We must carefully think the problem through before we act and try to adopt or we will only exacerbated our energy problems. Case in point is the rising natural gas prices and food prices because of the big push to produce ethanol due to the increase demand for natural gas and corn to produce the ethanol! To top it all off, ethanol get 30% poorer gas mileage which means you will have to purchase 30% more to get to meet your transportation needs! Ha Ha Ha! Are we learning yet?!