At the SAE Congress, Dr. Joseph Kanianthra presented data (Detroit News article here) that showed the relative death rates of car passengers, when struck by a light truck or SUV.
For example, in 2001, there were 1,163 deaths when cars were struck in the side by other cars. There were 2,008 deaths when cars were struck by light trucks, NHTSA's latest research shows. (nearly double)
NHTSA and the OEMs need to collaborate, and come up with a set of interface standards between light trucks and cars. Then, those standards need to be made mandatory, and NHTSA would require tests designed to these standards. These would be similar to the new IIHS side impact test, which simulates the high bumper of an SUV hitting a vehicle in the side.
I am not a structural engineer, so I don't know exactly how the new standards would look like. The crash structures of light trucks may need to be lowered to better interface with cars, and the crash structures of cars would be raised.
For example, I might require that light trucks have a subframe in the front and rear, which would contact most car bumpers in the event of a front or rear crash, preventing over-run. This sub-frame could perhaps be removable, for the 3 Hummer H2 owners out there who actually want to take their behemoths off-roading.
I would also require cars to have a strong high mounted side impact beam, and side curtain airbags, to protect the passengers if a light truck hits them from the side.