Nikon Rumors via Brad Hill has posted that there are whispers that Nikon is finally readying a flagship DX camera in the form of a D400 (or D500). Nikon Rumors had heard in the past that there could be a “double launch” alongside the Nikon D5, which has recently leaked and is expected to be announced in mid January.
From Brad Hill:
Anyway…in the last 10 days I've received 3 separate and independent communications (via email) telling me that a semi-pro (or even higher) quality DX body from Nikon is going to be announced in January. Two of these three sources have been spot-on in the past.
The interesting thing is that I'm getting scant specs, but those I am getting are consistent from all 3 sources – DX format, 10 fps, a “very good” buffer and selling for around $2300 USD. This consistency could say something about rumour credibility (or it could mean all 3 of my sources got THEIR information from the same source). Note that at least one of the sources derives their income from Nikon.
Nikon Rumors themselves have yet to receive anything reliable on the subject, but that could change shortly.