Dailmer Chrysler / Jeep were to put a Mercedes 5 cylinder diesel in the small jeep, Liberty I believe but I don't know if it ever happened.
I too would love to see and think it could be done, an efficient diesel in a mid size to full size 1/2 ton pickup. But with the cost of diesel fuel, diesel oil changes and maintenance of diesels and the improvements in direct injection gas engines (if they prove themselves) power and fuel economy I will be surprised in diesel makes a come back in those areas with the increasing restrictions being placed on diesel emissions.
PS
While the rest of the 3rd world countries thrive on cheap diesel and run terribly in-efficient polluting old as well as new diesel cars and trucks, often being built in a country with tighter emission standards than our country, at a lower initial and ongoing cost than north America probably. What happened to our manufacturing infrastructure after WWII, Korea, Vietnam? I am only 55 and know much just from reading, watching Public Broadcasting, Smithsonian, History Channel and Military channel but I am sure there are many that are only a few years older that know much more.