Don't forget, by the way, we have to power electric vehicles with something. I expect as gasoline rises in cost, electricity is going to as well, offsetting some of this differential.
It doesn't have to be that way, but what with our fear of nuclear power...
Anyway, I am completely in favor of electric vehicles for many reasons, but to call them inevitable within the near future, I think is unrealistic. Unless we come up with capacitors of wildly improved energy density (on the order of 1,000x) at which point I hope and expect the gasoline automobile market will fold overnight.