>... >I hope Nikon uses the D4 battery in the new D400 if/when it >comes out, as I think that body would be a nice complement.
I doubt that the D400 will use the EN-EL18 D4 battery. Most likely the D400 will be a D800 size body and would use the EN-EL15 from the D800, D600, and D7x00. Because it is much larger, the EN-EL18 battery takes up too much space for a body without a built in vertical grip.
The EN-EL18 battery can also be used in the MB-D12 vertical grip for the D800, so it's possible there will be a vertical grip for the D400 that will accommodate the EN-EL18.
Gary in SE Michigan, USA. Nikonians membership - My most important photographic investment, after the camera. D4, D810, D300 (720nm IR conversion), D90, F6, FM3a (black), FM2n (chrome) YashicaMat 124, Graflex Speed Graphic 4x5 My Nikonians Gallery & Our Chapter Gallery