I am in the process of figuring out the costs of converting a gas car to electric. Its not cheap.
The best kit that I have found so far is for a Porsche 914. You spend $2-4K on the car, take out the engine, exhaust, gas tank, etc. Then you put in an electric motor (mated to the transmission), batteries, controllers, etc. The kit is $13K and doesnt include the $1000.00 for batteries. Im still gonna do it probably, but its going to hurt my pocketbook for a while.
It will have a range of about 50 miles- which is plenty for most commuters. I will keep the VX for hauling and the weekends and long trips.
Granted, this is a very specialized industry right now. As this becomes more popular to convert to electric (and Im sure it will), and the battery technology gets cheaper and lighter, it will go down in price. But it will take a while and its wont go down that much.
So I think all the gas cars will stick around for a long time until:
1) Gas is too expensive NOT to convert or trade in for an electric vehicle
2) the government bans gas vehicles (yeah, right!)
3) the conversion to electirc or hybrid comes down in price enough that most people can afford it, and it supplants the cost for gas.
The reason I say all this is that its really not an option for most people to convert, as it is pretty expensive and it will require them to provide the maintenance on the vehicle in most cases (until there are garages that work on electric vehicles). With smoking, that required inaction to make it happen, and no money down. Converting to an electric or hybrid car requires action: either buying a new car or converting a gas one. Both of which require time and money.
But I do agree that gas cars will become "unfashionable". Especially the guzzlers like large SUVs and hummers and such. Its going to take a bit longer for that to happen though. Even here in LA where it seems like every other car is a hybrid. I think that right now is when the 50-year clock will start, not the 1970s. So around 2060, most gas vehicles will be phased out.
But like I said, I live in Los Angeles, where everyone talks about that stuff a lot more (or so I am told).
Just my 2 cents, not worth much more. :-)