Actually, torque shouldn't be an issue with hybrids, at least conceptually. The electric motor assist is why - electric motors have %100 of their torque available from 0 rpm on. Once the payload is moving you shouldn't need the assist unless you get to a hill or something. Using the assist continually until the juice is depleted would be the problem. I haven't checked on specs for the current crop of hybrids if they even rate for towing, but if they do I wouldn't expect the rating to be that different from any other car that size. The issue may be more that the transmission and rest of the car is not meant to handle those kinds of loads, or the duration of drain.

The torque characteristics of the electric assist is one of the reason the domestic manufacturers are targeting trucks for hybrid technology - more off the line payload moving capability. But Ford is supposed to be coming out with a hybrid Escape - smallish SUV with the same grunt but better mileage. Not sure what the current schedule for availability is, or if it's been scrapped.