Summary
GM's Volt will create demand for another generation of hybrid vehicles. GM does possess the resources and skills to bring this vehicle to market. Doing in "on schedule" may not matter if others have not made progress in the all electric arena.
Analysis
More than any other automotive OEM, General Motors has diversified its testing efforts in creating hybrid vehicles. While they are not the most notorious with the existing cache of gas/electric models, they have been diligent to try to develop other systems benefitting all of their models (who would've expected a HUMMER flex-fuel hybrid as was showcased at the 2008 NAIAS in Detroit this past January?)
The Volt, if it is the first all electric, mainstream body styled vehicle, will absolutely get the attention GM deserves. Will it be a high-volume model? Unlikely, and of course, the whole battery technology to enable a plug-in is everyone's dilemma still. But GM has shown commitment to their overall alt. fuel strategy and appears to be delivering on it in a stead manner with other models slated to release this year and in 2009.
The fact about alt vehicles and consumer demand is this: (1) "hybrids" (however you define them these days) are an area of interest by car owners that has shown positive payback so far to existing hybrid owners. The technologies used in production vehicles do work, so the consideration for future hybrid models will exist simply because the market trusts they are sustainable and reliable. (2) But the education needed from the industry is substantial. While most consumers are not your typical "first time/early adopters", those that do believe in something such as a Volt or a Honda FCX (fuel cell based in this example) will provide your classic opinion leader voice needed on the street. They just need to believe it will work for them as an owner and that the benefit will outweigh the incremental cost when purchasing these new vehicles.
GM has the ability. And if they deliver first, whether it's on schedule according to their original plans, or not, the market will show due interest. Given the past EV1's niche appeal, GM also has credibility for having an all electric vehicle which gives them an edge when touting the Volt.


