One of the key things about camera comparisons is that not only are they NOT standardized, there's no way to standardize them. The best comparisons are done by experienced photographers who look at both cameras and then come back with a menu of differences, that the potential buyer chooses from. You may get better resolution from a 1DsIII than from a D3 (actually, you will) but there may be complicated arguments about color, about ISOs, about ergonomics, and about end-use, that make more difference to a specific photographer than ultimate resolution.
Sharpness and resolution are different, though tightly entangled, especially in landscape work. If you take a photograph of a mass of millions of leaves in a tree, the resolution is whatever it is; but post-processing sharpening will find the edges of those leaves, and emphasize them essentially by darkening that line. With detail that's large enough to handle the sharpening, but small enough to really need it, good sharpening will fool the eye into believing there is more resolution than in a non-sharpened photo...but there isn't. It's just that the edges have been artificially sharpened. Think of one of those old paintings by somebody like Fragonard, where he actually drew thousands of leaves -- you don't actually see a tree that way, from any distance at all (you see a dark mass of leaves), so what Fragonard's drawing each of each leaf does, actually, is artificial sharpening... 8-)
You also have to consider that DPR does its tests with .JPGs, and quite a large number of photographers have said that Nikon has made a deliberate series of design decisions that require its photographs to be sharpened to taste in post-processing, to get the best out of them. Whether or not that's BS, I couldn't say, but might explain why a tester might think that it's good to sharpen a D300 but not another camera, where the JPG is made through a different process. In other words, he may be trying to balance the different problems, by comparing best-to-best, rather than whatever comes out of the camera, to whatever comes out of the other camera, figuring that most people who buy that level of camera will be sophisticated enough to understand the problem...