I haven't looked at the NPS equipment list in a while... but i was shocked to see the D600 on the list.
IMHO, the D600 is an 'entry-level' FX camera. I always took the NPS equipment list as Nikon's idea of what pro's need (or what Nikon thinks they need).
The D7000 only makes the list as a backup body. But isn't the D600 basically a D7000 with an FX sensor? I've been told the D7100 won't be on the NPS list (much like the D7000 it can be a backup body) even though it will have better build quality then the D7000 (full weather sealing,slightly larger grip.. etc).
Seeing that the D300s is the newest DX body on the list, does that give you hope for the D400? Or does that make you think Nikon has given up on DX for NPS qualifying equipment?