It's a great deal, for sure. I was tempted myself to pick one up, but frankly, since my work commute is one block it really doesn't make sense for me.
I did get the chance to drive one, and the full torque at zero rpm pull of an electric motor is quite fun.
As for incentives - yeah they have to be there. All electric and hybrid cars can acertain their success on tax credits and carpool lane exemptions. An ICE powered car is just cheaper to make.