James Assuming you're referring to the reduced frame rate for the D300 when shooting "14 bit" rather than "12 bit" NEF/RAW, the short answer is YES, the D700 will shoot "14 bit" NEF/RAW at the appropriate frame rates of 5fps w/o grip and 8fps with grip. Although most of the D700 reviews to date only state that the maximum frame rate/burst speed is 5 and 8 respectively, it means the same for all file formats, including Tiff, Jpeg and both "12 bit" and "14 bit" NEF/RAW. The published specs for the D300 specifically qualified the "14 bit NEF/RAW" frame rate as 2.5fps, while the D700 does not. Of course, the D300 will shoot at the maximum frame rate of 6fps w/o grip and 8fps with grip for all "12 bit" file formats.
For more specific information on this issue, read the following review posted by Rob Galbraith, where he states:
"Nikon EXPEED technology, including 14 bits per colour analog-to-digital conversions up to the camera's maximum frame rate and 16 bits per colour digital image processing, also carries over from the D3."
He has always been the most accurate source for this and most other professional photographer information. Here's the link to his review: