I'm surprised toyota would put an american powerplant in it's own truck. The cummins has a million gigawatts of power but it's rubbish compared to the long lasting fine diesels that toyota already have ?? Particularly in their Hino division ??
maybe it's all about marketing - north americans know all about cummins so maybe that's the angle they are running with
Toyota and the rest of the pickup makers all had plans to introduce light duty diesels in and around 2009. They all scrapped their plans because the engines they had planned on using were too expensive and they couldn't make the business case. Ford had a 4.4L V8 that eventually went to Range Rover, GM showed a 4.5L at the SEMA show in 2007, this Cummins 5.0L was originally developed with the intent of using it in the Ram 1500.
This latest move to diesel engines is being forced by the changes to CAFE standards, but diesels are subject to even higher emissions standards, making them more expensive again. That's one reason why Chrysler is using the MV Motori V6. Ford may or may not use the Lion 3.0L V6, but they are using the Duratorq 5 cylinder in their Transit, GM is considering the 2.8L four cylinder from the Colorado coupled to the ten speed for the Silverado/Sierra.
Resurrecting the Hino project would be more expensive than sharing the Cummins with Nissan, an engine already developed and with a good brand reputation. I have my doubts that this will come to fruition though.