I have old D300. And still I do not see reason to upgrade. Frame rate, megapixels, AF points all is not important from my side.
If someone needs them - buy camera that has it.More megapixes, more CPU time, more battery energy, more disk space...biggest isue - when I shoot uncompressed RAW with D300 from red LCD screen - I asuume image should have mostly red pixels. I expect RAW has some like EE88 0023 0161 ED55 0034 0211 binary patterns. But it has some garbage in which red color is received by green and blue channels about 30 percents.
So camera has more megapixels than color filter can support. And till now there are was no words about color filter.Of course I wait some in-camera GPS or wireless GPS by bluetooth.But last one feels impossible to accept from Nikon marketing.
And some very crazy idea - interchangeable sensors. Need more megapixels - buy one. Need more speed - buy less megapixels. Is some sensor dirty - buy another one and replace....