In 3 years time, I would be surprised if the Nissan Leaf didn't offer close to 200 miles of all electric range at roughly the $30K price point. Remember that while battery tech has only advanced 6-8% per year, this was in a market that was not nearly as hot or explosive as it is today. Nearly all the car manufacturers have a hybrid/electric program. Similarly, there are many more dollars chasing EV tech. So I would expect the rate of innovation to accelerate over the next few years. For GenIII to be competitive in 3 years time, it would need to offer at least 200 miles of range in a sportier, luxurious package. You guys may have noticed that the next model year of the Volt increases MPGe rating by 5%, also improves all electric range by 9% and also has notable reductions in emissions (ala the 'California package'). The field of efficient auto alternatives will get more intense over the next few years.
Remember, not only battery tech affects EV range. Cd and weight are huge factors as well. I've always thought it was silly that you need 4,000-5,000 pounds of stuff to move 200-600 lbs of people matter (I say this knowing full well that my car weighs 5,300lbs). If Tesla can continue to shrink and weight-reduce components like the motor/inverter assemblies, reduce chasis and infotainment weight, etc, then that will also drastically improve range. If the Model S went from 4,000lbs to 3,000lbs, that would translate into 25-33% increase in range alone!