How about this irony? I'm hoping for a new, improved Nikon DX DSLR, and I don't even like DX format! In fact, I kind of hate it, especially now that the D600 is the same size and weight as my D7000.
I have only two DX lenses (16-85VR, 35 f1.8), and a whole bag of AF and AFS film and FX lenses. I hate that my 18-35, 28-105, and 24 f2.8 are lenses I never use anymore (mostly because they are weird focal lengths), and that I need to spend another $900 if I ever want wide angle again. All this, and I also get poorer low ISO performance for action shots.
But,...I just LOVE two things about DX. 1) That my 70-300VR is a 105-450mm equivalent for shooting outdoor sports. And, if I ever get an upgraded 80-400VR, it will be a 120-600 equivalent. 2) That I can buy a 6FPS, full-feature DSLR camera for under $1,000.
I don't think we'll ever see a D400, but I do agree with Eric. I think a much improved DX camera will be released this year, probably in D7200 form. But, this may be the last of a breed. Only time will tell.