So far I've found 2 sites hosting sample images taken with Nikon's new beast.
Nikon official site:
http://imaging.nikon.com/lineup/dslr/d4/sample.htm
Joe McNally has secretly been testing it out for a while:
http://www.joemcnally.com/blog/2012/...ooting-the-d4/
And lastly here you can find a high res ISO 6400 jpg:
http://blog.gsmarena.com/nikon-d4-fi...t-as-expected/
Direct link to the image: http://www.nikon.com.au/tmp/AYl/lMj/...oT/gVE/Zob.jpg
:Whoa!:

