I think Ram hit the market square pretty much square with the Eco Diesel. Good MPG, towing numbers in line with middle of the road half tons and priced well enough to keep them moving.
The XD hits nothing. The MPG is poor, price is high and capacity is inline with high end half tons with similar payload capacity.
I don't think anyone is purposely trying to urinate on Nissan's corn flakes here. However few people are seeing this XD as a path to success in the fullsize truck market.
Drop the MSRP by 10k and that could change things considerably. MPG is still pretty miserable, that will be ok for now, but when fuel goes up again that could be an issue.