This dream is never going to happen. First of all GM says they'll just move ahead with the car design and hope the battery technology catches up. Second they have added a gas engine to "charge the batteries", so now it is a PHEV. Third, this whole Volt thing has been a PR stunt by GM from the getgo to get some good Greenie publicity.
Finally ,the way GM is going, they will be bankrupt before any Volt ever makes it to a showroom.
If you watch the documentry Who killed the electric car. This is the second generation of the EV 1. There is a small gas turbine the apparently with start when the battery is at 30 % of capacity. If GM is pouring money into this project it is more that a PR stunt. John McCain is talking about it.