Among those that intended to build diesel pickups was Toyota http://greenfuelsforecast.com/ArticleDetails.php?articleID=425

Now in the wake of Chrysler launching a diesel Ram and Nissan announcing a Cummins diesel for its next-gen Titan, Toyota is back on the compression ignition bandwagon. So far, GM's ready for production 4.5-liter Duramax V8 remains on the shelf http://green.autoblog.com/2010/06/11/general-motors-4-5l-light-duty-diesel-v8-was-on-track-for-25-mpg/ but it could be revived. GM has already indicated that it will offer a smaller diesel in upcoming US versions of the Chevy Colorado and GMC Canyon mid-size trucks. 

That leaves just Ford which has given no indication that it will offer a light duty pickup diesel. Ford will offer a 3.2-liter five cylinder diesel in the upcoming Transit full-size van and the 4.4-liter V8 it had planned to install in the F150 a few years ago did end up finding in a home in European market Range Rovers. For now, Ford remains committed to gas-fueled EcoBoost technology for the pickups. ?