If you are going to write a negative commentary about something, it's probably not a good idea to have a fundamentally incorrect statement in your opening sentence. IDC Energy Insights research manager Sam Jaffe opens his criticism of General Motors' Chevrolet Volt strategy by stating "When the Prius launched in 1997, a new term was born in the auto industry: the "halo car"." He then goes on to say the Volt is a "helium" car because it is "a car whose express purpose is to raise the overall mileage number of a particular carmaker's fleet."
The general concept of the halo effect dates back to at least 1920 and a study by Edward Thorndike. In the automotive context the term halo car had been used for decades before the Prius was conceived. Jaffe's arguments don't get much better from there beginning with the inaccurate assertion that Nissan has cracked the code for making cheap lithium ion batteries. He references a $9,000 battery price, but that has already been refuted by Nissan as a future target, not the current cost.
Then there are GM's volume projections which Jaffe believes are just enough to pull up GM's CAFE numbers without being high enough for Volt to make a serious dent in petroleum use. While GM will no doubt benefit from the CAFE effect of the Volt, the projections are more likely to be based on what GM expects it can actually sell at the Volt's likely price point, something that is itself driven by component costs. GM can't afford to eat too much cost on the first-generation Volt, and the second-generation model is expected to bring that down significantly.
As for Nissan's volume projections, it remains to be seen if it will be able to get anywhere near half a million units a year once people actually start trying to live with EVs like the Leaf. Just because Nissan is keeping the price relatively low (at least compared to previous EVs) that doesn't necessarily mean demand will materialize. The sales might become a reality, but at this point, it's far too early to tell.