What are the reasons not to switch to all electric right away?
1. It's new and scary. The big car companies don't like it, and the consumers don't like it.
2. The volume is very low, so they are very expensive in purchase.
3. The oil companies don't like it, as they run on selling gas.
The first one is being adressed by the specs of the new breed of all electric supercars. Although the design and marketing are still way beyond the regular supercars. But, given the same manufacturing and marketing budget, the electric one easily outperforms any ICE car in existance.
The second one is the classic chiken-and-egg one, and can only be adressed by simply waiting (so the other producers who want efficient batteries make the volume rise), or some big volume contracts from large car manufacturers.
The third one is probably the hardest one: the oil companies are very rich, which is why they demand some solution that uses a fuel that can be pumped at the gas station, which they can produce. A liquified gas is fine.
It isn't that simple. An electric car cannot provide the same things that and ICE can. Sure it provides other benefits, but unless it can match an ICE it will never replace it.
That is why I like PHEVs. They allow us to get all the advantages of an ICE (no limit on how far you can drive except the speed limit and you bladder, and gas tank).
Unless a battery can be recharged at the same speed that you can fill up your tank an electric will not replace an ICE. And that will likely never happen. The infrastructure would be crazy expensive just to provide enough power to make it possible even if the battery technology was available, and it isn;t...
This might work though, but still expensive
http://www.youtube.com/watch?v=f9bc4vNccL0&eurl=http://www.ecogeek.org/content/view/1233/