If you are right about the fps limitation at 24mp then I agree, there will be no D400 if Nikon can't squeeze 8 or even 10fps with grip(?) out of it. I don't understand how the Nikon 1 series at the bottom of the lineup smokes the #### out of the rest of the lineup.
The 91,000 point metering enables better Auto-Area-AF, 3D-Tracking, and Face-detection. So it is an important feature to overall system performance.
I suspect a D400 is coming. Maybe the wait has been CPU power? Maybe the wait has been adopting the 1-series DNA into DX. If Nikon can move the 1-series tech up the lineup and into the D400, that would be a stunning coup. I'm not sure if Nikon is ready for that yet, but I and many others would buy even a "conventional D400". Anyhow, I am way less worried now that I see the D7100 specs (which is a great package all the same).