Some interesting facts about Nikon DSLR body design:
The 12mp D3 sparks a new era as it marks the very first full-frame DSLR in Nikon's history.
Designed by Giorgetto Giugiar, (Italian automobile designer) who is also responsible for the F3, F4, F5, F6 and D2H/D2X.
The above image (which was also featured in Nikon D3 product brochure) shows various prototypes that influenced the final D3 design.
Upon a closer look, "D2H" was the initial designation for this new body design. This probably shows that Nikon had already planned for a full-frame body since 2003!
Another side note, the "red swoosh" below the mode dial and red vertical line on grip (previous models) was Giorgetto's "signature" on Nikon cameras. According to him, the rational behind the "red swoosh" is just for aesthetic purposes.
Below is a brief interview of Giorgetto Giugiar on the development of Nikon D3 design: