Actually, Chrysler, Ford, GM and I hear Toyota are coming out with a diesel in the 1500 class Pickups and probably larger SUVs. I think some of the offerings should be out mid to late 09 and other by '10.
Some of the article rings true. You have to sell so many of any engine to recoupe your cost. The smaller the engine, the less profit per engine. So you have to sell more. It was mentioned Ford felt they needed to sell 350K per year. Thats a lot of engines. If the engine would fit other platforms, then it might be doable. I don't know if it would be big enough for other cars and smaller SUV and trucks.
Tom