I agree with most of the comments that DC fast charging/Tesla type super charging is not really needed for the Volt.
I DO think, though, that faster charging, even if only 6.6 kW charge rates, would be really useful for a substantial portion of the Volt buying public. I frequently drive 60 or 70 miles and being able to get 20 miles per hour of charging while taking a lunch break (instead of the current 10-11 with the 3.3 kW charge rate) would really make a difference. It would also make using public charging stations that charge by the minute make a lot more sense than they do now.
Is it a make or break item like more AER, lower MSRP or roomier back seats/seating for 5? Probably not. But it would help me decide on a Volt when my current lease runs out in 2016, instead of another plug in choice. Heck make it an option, I would pay $500 to get it, maybe more, and it would cost GM a lot less than that to do the upgrade.