Pixel-peeping: Nikon D4 studio test samples at IR [updated with more]
UPDATE (March 1st, 2012 at 7:25pm NYC time): More studio-test-samples have been added, included RAW samples - at the same page as before...
ORIGINAL POST: Imaging Resource has published their first wave of Nikon D4 studio test samples which you can use to compare with any other camera in the IR camera database using their Comparatometerometer. Of potential interest are comparisons to the Nikon D3s, D700, Canon 1D Mark IV, etc. As far as I can tell there is no way to create permalinks of pre-filled comparisons, so that adventure is DIY. Make sure you align the test-samples of the second camera with the available D4 test-samples since the D4 does not have the complete set yet.
In terms of availability, the D4 is in pre-order status.