A true D700 successor: D600 sensor in D800 body ... and fur gods sake, leave the damn video out!!!

I don't know if they will be called that but I agree that this will be the case.  They have to come out with new cameras so they'll fill these slightly minor gaps in the lineup IMO.

There definitely is space for a D300s replacement and D700 replacement in the current lineup.  These are easy gaps for them to fill because they'll leverage existing components and tweak them to make them better rather than bringing in all new components such as entirely new sensors for the D600/D800.  I can easily see either a 16 or 24 MP D700 type successor that approaches the ISO sensitivity, AF speed/accuracy, and frame-rate somewhere around the D3s or D4 level.

It will come because it makes sense(not because I'm asking for it) and we just need to be patient.