For driving around in a company electric car and other small applications, no problem. To replace a car the average Joe uses to go any place any time he needs to, not anytime soon. Joe can't afford to have a spare car parked to make up for the shortcomings of the electric car.
Battery technology is nowhere to that point and burning dirty coal to power a clean car doesn't make a lot of sense to me.
Now, lets dream for a moment. We have nuclear and hydroelectric plants pumping out all the juice we need, we electrify the highways with a third rail or something more appropriate so that I can drive all the way to Dallas and back and you got yourself a winner.
Electric cars make sense RIGHT NOW if you're commuting (or delivering stuff, or whatever) in an urban environment, because you can charge overnight/while-at-work/whatever. I know people who live in Chicago who rely on public transportation day-to-day and rent a car if they need to leave the city. I can see a similar system working with electric cars instead of public transport; I wouldn't force anyone to do that, but people may choose to do it themselves just to save on fuel and maintenance.
I don't think that electrifying the interstate system would really be practical, but then I'm not an electrical engineer (though I often have to pretend to know what they're talking about at conferences).