I don't think the fares on JFKNRT are as much of a problem as the fact that the 744 is the only plane that NW can use to fly the route. UA and AA both use 777s which is probably the right size for a market with 4 US flag carriers (including CO from EWR) plus a growing number of foreign flags from JFK to other Asian destinations. I've met a number of international students (esp. Chinese) from the eastern US that have been routed on NW via JFK so it's obvious they are pricing at the bottom of the barrel in order to fill the plane.
Also, this is indicative of the shortage of long-haul equipment in NW's fleet. Since this 744 is going to replace the 742 on LAXNRT, it says the 742 has no place in passenger service.
I've got to believe DL has got to be considering flying this route now, esp. if they agree to codesharing beyond NRT w/ NW - something that is currently not done because of the Korean relationship. Not being able to put their code on NYCNRT is a big hole in DL's route network. Also, DL has plenty of traffic into JFK to feed this flight, something NW does not have; DL has more connecting service and a stronger commitment to JFK than they did pre-9/11 when DL operated this route w/ an MD11.
DL's 777s make much more sense flying a route like this than NW's 744. I fully expect that DL is talking w/ NW about serving this route starting in the spring.
