The LL test is not a fair reflection of what the Leica can do at full-frame. By producing a common crop size for the two from the same viewpoint, itís essentially comparing a cropped Leica with the NEX, not an FF with APS-C. In effect, a 24MP APS-C camera (albeit with downsizing to 18MP) and an 8MP APS-C crop of a full frame. (Even if it's only common FoV sub-crops which are compared, that ratio of 3:1 on "native pixels" and 2.25:1 on "downsized pixels" still holds). It is hardly surprising that the NEX then out-resolves the Leica as it's effectively just comparing the resolution at the sensor which (if the lens is good enough) is bound to favour the NEX. The Leica is simply using less than 45% of the total pixels in the frame (or about 67% of the line-pairs across the whole frame).
You cannot perform a proper test of two different lens format sizes without doing one of two things. If you must use the same prime lens, you have to move the small sensor camera further away to match the FoV of the larger sensor. This canít be perfect, as perspective will change, but for two-dimensional subjects (where the subject plan is parallel to the cameraís focal plane), or for subjects far enough away that the depth isnít an issue, it allows for comparing resolution. Note that it is theoretically necessary to alter the aperture as well to equalise the DoF, but this introduces other lens issues Ė however, if resolution is compared at the common point of focus on both, then this is not an issue. To avoid any diffraction limiting on the NEX-7, an aperture of F8 or wider must be used.
However, if you want a full comparison of the two different frames, you have to take two photos from the same place with two different lenses with focal lengths chosen to give matching FoVs. Also, the aperture on the smaller sensor has to be wider to equalise the DoF. Of course, using two different lenses introduces another, major, variable, but itís the only way of truly comparing two images taken with cameras of different sensor sizes with the same perspective.
Ideally the test would need to be repeated using a 50mm lens on the Leica with a 35mm on the NEX-7 of similar quality (with a little bit of shuffling of the tripod position to equalise the two FoVs). The NEX image should be shot at (say) f5.6 with the Leica at around f8. I would then compare an NEX-7 image downsized to 18MP with the native Leica. However, if you want to compare with the NEX at its maximum resolution, you'll need to up-scale the M9 image to 24MP.
Note, I don't own either of these cameras (albeit I have a Sony A700), so I've no axe to grind in favour of the red-spotted one, but I do think the result doesn't reflect the natural advantage of the M9's larger sensor size.