I worked on electric vehicle space in early 2000s - there are many improvements for sure since then, but in the battery technology, not much has changed. 10 years ago, top of the line 18650 Li-Ion cell (same ones used in laptops and the Model S) weighed 46g, had capacities of 2.6Ahr, and cost about $10 a pop. Now, it weighs the same but have capacities of about 3.4Ahr and cost about $5. 30% improvement and half the cost is nothing to laugh at, but that also took 10 whole years!

The biggest problem with batteries is that they're chemistry-bound - you don't get the free twice-every-2-years type of thing that we're used to in computing world.

Even with the Nissan Leaf type of vehicle, the growth in battery capacity and more efficient / lighter chassis may result in extension of range to, say, 150 miles from 100 miles by 2018. Will that make it a no-compromise electric car? What would the no-compromise range be?

Looking at what Tesla has done, and what Elon has said (who actually very carefully said "sort of affordable" - http://greenenergyholding.blogspot.com/2013/08/teslas-next-e...) what's more likely is a new model starting at, say, $40k ($30k after tax credits) with fairly limited range, with really usable range starting at around $50k. Is that affordable? Probably not. But probably does fit the label of "sort of affordable".