This is usually a car enthusiasts web site but they have 9surprisingly) been reviewing a group of small cargo vehicles and they have taken a look at the Prius v as a possible light cargo vehicle: Commercial Week Day Five Review: 2012 Toyota Prius v – Take Two | The Truth About Cars The reviewer notes something interesting: Looks like the v will be even more versatile than we expected!
I use my Prius as a cargo hauler, the reviewer did very well. (He could have mentioned turning radius compared to a van)