Zete, you're correct - and I don't think the term "affordable" can be overstated in this instance. As one of the bloggers mentioned in the original article, the true impact of the Volt will happen when it becomes affordable to hundreds of thousands of consumers.
The year they sell as many Volts as Toyota sells Camrys, is the year that will mark the permanent and continual decline in fossil fuel consumption in the United States. The rest of the globe will eventually follow the U.S. quickly over the years following.