No, the DX sensor offers the cropped (apparent magnification) 1.5X perspective. A 300mm on a DX would appear to be 450mm. A 300mm lens on an FX sensor is a 300mm lens.
well, you will have 450mm but with 5mp. the D3 will auto-crop if you put a DX lens on it unless you tell it to otherwise.
Funny you would write that Gary, at least if it's not tongue in cheek. You just wrote today about how the D3 AF outperformed the D300 AF, and I expect that will be on of the primary differences between the D3 and D700.