The upcoming Nikon D4 will probably pop-up in April 2011 with 20 MP sensor (FX ‘FF’ and HD vid).
As posted in North Light Images
the D4 is slated for an early Q2 announcement (April?). D4 at ‘around’ 20MP (FX ‘FF’ and HD vid).The same technology will appear in the (DX) ~18MP D400.
The D700 replacement (D900), with similar video to the D4 will come along later (this year or next)
The D4 should actually be released by the end of the Summer.
As an event photographer often in very low light situations ( awards, school balls, etc) I can wait to get my hands on the D4. Yes I am paying for the extra video functionality – which I won’t use. But my work will be 10 x better.