This is what makes me think GM are serious about producing the Volt.
The EV1 never did fit into their business model. They produced something like 1,100 of them total, and they were built by hand at a very leisurely pace. They never designed any other models based on the EV1 architecture, they never made any variants or any sequels. There was no EV2. You could tell they weren't serious because that approach simply doesn't make sense in GM's business plan. Their business plan calls for making 100,000+ of something.
When the Volt was first shown, there was nothing under the hood. The styling elements were mostly borrowed from the Camaro, and it seems pretty apparent that it was cobbled together very quickly. It was something GM threw together as a quick response to the high-profile unveiling of the Tesla Roadster and the low-profile announcement by Toyota that they planned to make a PHEV.
Then GM showed it and got this huge public response that they didn't really expect. Now they're in the hot seat. . . There may actually be demand for 100,000+ of these things if they can build it. So they start asking themselves in earnest: can we build it?
As they've looked into the battery technology, which they first said "doesn't exist yet", they've discovered -- I think to their great surprise -- that it does exist. There are battery chemistries today that can be made to do this job, with a bit of tweaking and packaging. The main obstacle is an economic one, because the batteries they need aren't mass produced at an affordable price. Yet, it's apparent that they can be. Somebody just has to get the ball rolling.
Now they are showing the Opel Flextreme in Europe. They are talking about 60,000 units on the first year of production. They've devoted a large team to this project. GM may have been half-hearted at first, they may have merely been testing the waters when they first unveiled the Volt, but I believe that is no longer the case. The huge response from the public, the competitive threat from Toyota, and the positive response from A123 on battery chemistry have all joined into a "perfect storm" leading GM to commit to the E-Flex as a serious production platform.