I am surprised that the D4 is 16 MP whereas the D800 is 36 MP.
not entirely unexpected consolidation of the camera lines actually... same thing is happening on the Canon side as well: a "pro" model with vertical grip, medium pixel count, and high shooting performance (1DIV, upcoming 1DX), and a "pro-thusiast" high pixel count model (5DII, upcoming 5DIII), while their "pro-studio" line seems to have stopped with the 1DsIII (no 1DsIV)... so for Nikon, the upcoming D4 and D800... less models, greater economies of production...Something 'fishy' with nikon marketing strategy and seem like nikon is 'trying' to 'con' more people, I forseen a D4x or D4E or D4S... .. Just a matter of time, ... Just wait and see...
so for people who need fast, ultra long batter-life, and super-solid build, they have the "pro" model, and for people who just need the pixels, the "pro-thusiast"... the so-called "pro-studio" users don't necessarily need the ultra long batter-life and super-solid build of a "pro" body so they are rolled into the "pro-thusiast" line...