Yes. So in terms of settled street prices, the D4 is never going to fall below £4k, with the D800 at £2k-ish. Between them that's the D3s/D3x covered, not that the D3x is selling many, like the similarly doomed Canon 1DsMk3.
But it still leaves room for a D700 replacement, perhaps like a D800 but with a very different appeal using the D4's sensor with only 5-6fps and up to 8-ish fps with a battery pack, making it around a £2.5k total. Nikon will pitch it so that even if it does steal D4 sales, they'll still make money (not that I think it will, pros will want the D4's durability and all the remote connectivity stuff).
Then there's a big price gap down to the D300's £1k level that will probably be filled with a crop sensor version of the D700's replacement. It all makes sense to me at least