This person on Flickr seems to have a decent comparison:
http://www.flickr.com/photos/dos-chin/sets...6120567/detail/
Bill
An excellent example of what not to do. For the benefit of anyone contemplating doing a serious comparison between the P65+ and the D3X, one should (1) pay particular attention to equalizing the FoV in one of the dimensions, through choice of lens focal length, and (2) one should equalize DoF by changing the F stop by the same multiplier that has been applied to the focal length.
The photographer on Flickr has completely ignored point (2) and got point (1) slightly wrong. The P65+ shot uses a 150mm lens at F11. For a portrait aspect ratio, the equivalent FL for the D3X should be 90 mm, and the equivalent F stop either F6.3 or F7.1. The Flickr guy has used F13 with the D3X.
I think everyone except a complete beginner would appreciate that any good lens will be noticeably sharper at F6.3 than at F13 on a high-pixel-density camera such as the D3X.
In the following 100% crops, I downsampled the P65 image to the same file size as the D3X. If your monitor has a resolution of 120dpi, the 100% crops represent a print size of 33"x50". At larger sizes than this, the P65 would have a resolution advantage. In the crops below, the P65 actually does show a resolution advantage, but only as a result of an inappropriate choice of F stop.
[attachment=16795:P65_v_D3X.jpg]