While I would like to think the change will happen fast, I predict it will be a while.
For example if Tesla is wildly successful and produces double the planed cars in 2013 that would be 40,000. Let's assume Nissan is wildly successful and does sell 100,000 Leaf's and for argument sake lets assume the Volt is an EV and sells 60,000 units next year. That is a HUGE growth of 1000%. That would still only be 200,000 EV's sold in 2013, or about 1.5% of total vehicle sales. And if EV sales grows as 100% a year from then on it will be 2020 before we convert. Then since cars average a 20 year life even in 2020 gassers will still be over 50% of our fleet on the road at that time.
Then remember we are a long way from consider moving the long haul truck fleet away from oil power.
So I am afraid we will be dependent upon oil for a long time to come.