I suspect the D800/800E may be more than many buyers anticipated and they will be unable or unwilling to do everything that is required to use it satisfactorily. That's why I am keeping my D700 until after I use-test the D800E in its free-trial period. Even If I keep the D800E, I may keep my D700 for all the occasions where the D700 is just simpler and easier to use and also for lenses I like but which do not measure up to the D800's very demanding requirements.
I reached those conclusions after reading the Nikon Technical Guide several times, very carefully. I believe Nikon means what it says in this precisely phrased guide.