interesting. it sounds exactly the kind of thing Nikon would do. An affordable full frame when canon just made theirs 1K more expensive is a very very good strategy. specially if they crank the fps to 5-6, keep it to 16-24 MP and priced around 2K.
The Nikon full frame lineup looks could look like this:
D600 (low end, $2K, ~20MP 6fps)
D800 (mid end, $3k, 36.3MP 4fps)
D4 (high end, $6k, 16MP, 11fps)
D4X (high end, $8K? 52MP, 4fps)* assuming they scale up the 24MP D3200 sensor. The D800 has a scaled up D7000 sensor.