Just because the margins on electricity are so low, it doesn't mean that the infrastructure wouldn't be made available.
If you think about it, North America is already dotted with gas stations all over the place. Pretty much all of those are hooked into the electrical grid. All you would need is a couple of metered sockets, and you're good to go - your gas station is now an electricity re-charging station.
Swapping batteries might be good for a laptop, but swapping a 200lbs NiMH car battery doesn't sounds like my idea of a quick stop-over.
