I did a fair amount of math on the deal and wound up buying a pair of Prius Cs. This is for two active kids. I used a daily mileage of 40 with no charging stations along the way. All my calcs were done on base model cars, cash purchase. This takes out option changes, financing and lease deals so I could compare apples to apples.
The Contenders were the VW Golf Diesel, Hyundai Veloster, Prius C, Chevy Volt, and Ford C-max. I used the 8 year use schedule and calculated the time value of money at 5% just cause it was easy. the Volt came in second to last due primarily to the up front cost of the car. The Prius C edged out the Golf Diesel by a slight margin.
If the daily mileage were down a bit, and there were charging stations along the way, the Volt would have done better, but the base price of $36k was about $16k over the cost of the Prius C base model, and amortized over 8 years it didn't quite pay off. If we don't consider any time value of money, and freeze the dollar the Volt would have paid off right about 6.7 years.
The other thing I checked was the resale value of the Prius after 8 years and 120k miles. Quite impressive numbers, and I can't say what the Volt will be, but I guessed that it would be somewhat less. My brother in SoCal owns a Volt and his commute one way is 27 miles. He usually makes it without the engine coming on, but only if he doesn't use the AC. If he uses the AC(c'mon, it's SoCal), the car only goes about 18 miles on electric. He does benefit from driving in the HOV lanes alone, and he also gets some kind of state rebate on taxes which I didn't calculate because I"m not in CA. He put in a 240 volt charging station at his work but he has to share it with another Volt driver so he doesn't always get a full charge before going home, but hey, as long as the company is paying the meter, he takes what he can get.