the D700 is a wonderful camera. atleast that's wut i know. i got a chance to hold one, its a fren of a fren's camera. well obviously i dont know how to maneuver it.
the megapixel jumps from 12mp to 16 mp. that's a big different. but i read somewhere nikon put it as 12mp to gain better light-retrieval and to control noise at high-ISOs. for those who really loves to crop the 16mp can be nice, otherwise i think the 12mp is serving just fine. better fps than the d700 of course. and a video mode as well. well my current camera got this video feature and i dont use it that much. i only used it twice. first when i first got the camera so i wanted to try it, and the second time is when i was somewhere and wanted to try it again . the video feature is nice although i dont use it that much, its always there when i need it. wut im trying to say is, if i own a D700, i wud definitely keep it. but for those who use it for ur works and needs extra pixels/ISO range/more fps/bla bla..shud get it then. just my 2 cents tho im not a nikon user anyway.