This Nikon D400 rumor is coming from the Nikon Solutions show in Cologne, Germany (May 15-16, 2009):
Original German language source | Google translated text
I attempted to email the owner of the site, but his contact form seems to be broken. I am speculating that he received that info from somebody on this Nikon Solutions show. Let me just say that Europe, especially Germany is much more relaxed in terms of “leaking” info before an official release – we have received many good stories from Schland, so I would not be surprised if this one turns out to be true.
NR rating system: 60%
Here are some pics from the show: