Thought this comparative fatality statistic that just came up on the USA today site interesting:
Cruiser (low seat and center of graity): 5.7
Touring (powerful, heavier weight): 6.5
Sport (lightweight, built for speed): 10.7
Supersport (one-person racing bike): 22.5
Source: Insurance Institute for Highway Safety
Probably says a lot more about the experience and risk taking attitude of the riders

than characteristics of the bikes.