There are two set of tests, which were presented on a Japanese blog (Digital1gan).
Follow the links to view the full-sized high ISO test photos comparing the Nikon D3 and Nikon D700 in terms of image noise.
For those who don’t relish downloading such large files, Arturo Fukuda of Fotoactualidad.com has provided 100% comparison crops on his blog, plus started a discussion thread on DPReview.com: