I think this varies by location (and by brand of car).
A few years ago, they installed Tesla Superchargers up and down the 401 here in Ontario. You could comfortably drive your Tesla - but only a Tesla - from Detroit to Montreal without worrying about ever being far from a charging station.
I have some experience driving an electric car: at work, my department's vehicle is an all-electric Ford C-Max. Based on that experience, I would say that I could replace my current car with an electric car and have no change at all to my travel habits, even if I could only charge it at home overnight.
As it is, for any serious out-of-town trips, we use my wife's Flex as the "road trip" vehicle instead of my smaller car anyway, since the Flex holds more stuff and she can't drive stick (my car's manual).
We're starting to see more public charging stations and I've even been seeing a lot of apartment buildings that have at least rough-ins for charging stations in their resident parking areas, so I think you'll see it more and more viable for people to use an electric car as their main vehicle.
... and really, I think we're rapidly approaching the break-even point where, for most people, commuting with an electric car and renting a gas vehicle for the occasional long trip is going to be more cost-effective than driving a gas vehicle to work every day. For people with long commutes, they've probably already passed this break-even point.