Price, driving range and re-charge times (and building recharge stations) all need to improve for electric cars to really catch on.
As technology marches on, it will be interesting when Nascar and Formula 1 cars are all electric and self-driving...."Drivers start your engines" will be completely obsolete!
Price will get better as the parts availability, production techniques, and numbers improve, just like with anything else, it just has to get there. Range will improve as new forms of efficeny are discovered and added, plus with improvements in battery and charging tech too. From my experience with owning a flex fuel vehicle, charging stations will likely be the biggest obstical. You have to have people interested in building places (I give Musk lots of credit for that!), as well as taking efforts to deal with opposing parties (oil companies for example) on the construction of such places. If I had the money or knew the people, I would look into doing an alternative fuel "gas station" that covered the biofuels, ev charging, and alternaive petrolium fuels. I number of those along the major corridors and in urban centers could go a long way to countering those issues for all of us that own these sorts of vehicles.