I just recieved my D700 today and I noticed that above 1600 ISO I have a dead pixel. It appears like a blue cross when magnified 100%. Is this enough to take the camera back or is this normal at these high ISO. Thank you in advance.
Sounds like a stuck photosite to me. My D200 developed 5 stuck pixels above ISO 200 in the first 9 months I had it, so I sent it in under warranty. Nikon maps out hot or stuck pixels using firmware changes. About a month after it returned, my D200 developed another hot pixel above ISO 400. I sent it back again and asked for a new sensor. It appears that they did replace the original sensor, as the colors are significantly better and I have not had hot pixel issues in the last 9 months. Nikon does not pay for shipping to or from the repair center the first time, but they did pay for shipping both ways the second time.
If possible I'd return it to the place you purchased it for a new one, or else contact Nikon for a warranty repair. Nikon will warrant the hot pixel issue fix for 6 months after the repair, so if you wait until there is less than 6 months left on your warranty, you can get all problems in that area fixed at one time and extend you warranty a bit.
There is a freeware utility that you can download for checking on hot pixels and pixels that are marginal or going bad. It is called PixelFixer and is available at http://www.pixelfixer.org/ Note that the current version doesn't support the D700 yet. Since it does support the D3, I assume that changing the camera Exif to D3 via hex editor, should allow you to use the pixel check.
"... you see, but you do not observe." - Sherlock Holmes