CNN recently reported on a study done by the Children's Hospital of Philadelphia which gives us the shocking revelation that while SUVs have certain size-related safety benefits, those benefits are offset by their tendency to roll over in accidents.
This rehashes the difference between active and passive safety. Passive safety is the ability of a vehicle to absorb damage without adversely affecting its occupants. Crumple zones, seat belts, and general heft are means to this end, with SUVs and other large vehicles standing as examples. Active safety, on the other hand, is the ability of the vehicle to avoid the danger in the first place. Nimble handling and computer controlled stability systems contribute to this, as demonstrated by smaller, sportier cars.
While both are obviously important, it would seem to make sense that if the goal is to reduce and minimize injury, avoiding the accidents in the first place would be more effective.