Regarding Nikon backing away from DX in favor of FX to me is a question that is out of the question.
The two are totally different animals with different reasons for being...kinda' like apples and oranges.
If I want superb wide angle capability, I'll choose FX...and if I want to work with my long telephotos, I'll almost always go with DX for improved pixel density, the crop factor and with the D300, anyway, excellent high ISO performance up to 1600, easily, and beyond.
There's more than ample room for BOTH technologies and depending on specific need, each has its own place where its capabilities excel. For example, if I want to mount my 200-400mm AF-S VR and a TC-14E, it'll always be the D300 or my D2Xs that I'll reach for... On the other hand, if I want to use my 28-70 f/2.8, the D3 will always get the nod. It's just that simple...
Viva la Difference' or something like that...
Dick The Long Ranger A Telephoto Lovin' Nikonian
"There are none so blind as those who would not see..."