In one or two more generations, people won't have any attachment to old combustion engines and they will seem like ridiculous ancient technology.
I love the sounds, feelings, vibrations, scents etc of normal cars but the Tesla is a flat screen TV emerging from a world of CRT's. A complete replacement once costs are down.
It will be a while yet. There's basically two types of EVs out there.
1) Cars like the Model S. They're built for the luxury market. Get comparable range to petrol cars in their class. But at a very high price. The Model S starts at $70k+, which is more than a BMW M3. Yes, there's almost no maintenance cost but its still out of reach for a big chunk of car buyers
2) Semi-affordable city runabouts that get about 60-80mi of range. It's good enough for short in-town hops but not for regular commuting on the highway. Especially since most businesses won't have charging outlets available. Commuters tend to make up the bulk of car buyers though, where city folk prefer to take transit rather than own a car. These EVs also tend to cost double what a comparably equipped petrol cars costs. The iMIEV for example costs $10k more than the Prius C in Canada. That's 10 years worth of gas for the Prius according to the EPA. Fuel prices just aren't high enough to make the economically viable.
Unless there's a huge spike in gas prices, or there's a quantum leap in battery technology, EV adoption will be gradual. Lithium used in EV batteries is difficult and costly to mine. Plus China holds much of the world's supply. Batteries are the biggest cost of producing EVs and hybrids.
There's been talk of swappable packs. Drive up to a station that just puts a new one in. Which I don't think would work on the real world as you'd need standardized battery packs for all cars. Which ain't gonna happen.
I'm hearing promising things with graphene super capacitors. I think that will be the future, though they're still in the prototype stage yet. If they get them doing as promised, it will be a fundamental game changer in the automotive industry. Cheap, clean vehicles that can charge as fast as it takes to fill a gas tank.