I have a pretty reliable source for Toyota and he explains that currently Toyota will not enter the diesel truck market. The EPA keeps changing the requirements for diesel emissions. Personally I would like to see a gas Yota Dually. Just get us the Heavy Duty truck, I am buying Fords with the 6.2 gassers and have a lot less issues than we did the with the diesels.
Personally I think diesels have become over rated, I see guys buying them to pull a boat trailer or 28' camper. I have no troubles pulling 15k trailers and do it monthly, my f250 with 6.2 gas just rolled its first 100k. I have not had any issue yet. If yota would put a dually out with a good gasser, sign me up