Well, there is this small matter of cost & range. Eventually the demand will depend on price and availability of oil i.e. how will Peak Oil play out.
The Model S has a range of 300 miles, which is typically more than the average commuter will use in even a week's time, and it's price of approx. $50K is comparable to any number of other high-end, luxury, sport sedans both on the domestic and foreign markets. After that, it really does all boil down to availability &/or profile, i.e., people actually
SEEING it.
By way of explanation, it is commonplace knowledge that we live in an image conscious society (albeit World) that favors visual and physical stimuli, one wherein people generally have a hard time with believing in that which they cannot actually see or touch, let alone grasping a concept that is, admittedly, to most of them little more than futuristic science fiction.
The mass production and deployment of the Tesla models will serve to embody the 'concept' in
tangible reality that will prove to be far too hard to ignore or be so easily discounted by conventionally fueled vehicle proponents, ultimately serving to signal that the future is here NOW and that electric powered vehicles are a
reality.
As for how "will Peak Oil play out...", well, they're doing quite the job of validating ALL of the so-called "greenies" allegations of the impropriety and danger of off-shore drilling, as well as backing themselves into a corner with first the occurrence, and then the rather conspicuous handling, of the Gulf Coast oil leak, wouldn't you say?!
Alas, this thing from the past (petroleum from decayed plant life) will find itself left in the past as we move on towards the future in commuter, commercial and industrial powering...They're just making the case for the need of transition that much more obvious and necessary.