I won't get to put my 5DIII through the ringer until tomorrow, but since I had to take a few snaps of my 1DII which I'll be getting rid of soon, I did get a chance to at least take it out for a test run. All images are out of camera raws converted to jpeg in CS5. Neither lens used has been micro adjusted yet.
Focus point was the "Canon" logo using automatic AF selection. Shot with 24-105L at 105mm: f/8, 1/125, ISO 100
Focus point was on eye cup using zone AF selection. Shot with 24-105L at 105mm: f/8, 1/180, ISO 100
Focus point is where the label reads "Complies with the Canadian..." using auto AF selection. Shot with 70-300L at 260 mm, f/8, 1/180, ISO 100
Old film habits die hard, so I usually manually focus for stuff like this. For the sake of testing out the AF system, however, I tried out auto, zone, and spot AF selection, and had pretty good luck with each of them.
Each one of these were also shot as jpegs in the "Standard" picture setting, which is set at "3" for sharpening on a 0-7 scale. Not surprisingly, the jpegs were just a hair sharper, but not any sharper than the raws once a smidgen of unsharp mask was applied. There was just as much detail, particularly in the rubber grip areas, in the jpegs as in the raws. Based on some reports, it sounds like the jpeg processing is obliterating the detail in camera, but these images escaped unscathed.
This is obviously a very small sample set, so I really need to take the camera on a real shoot before drawing a more definitive conclusion. Considering that the 24-105 at zoomed to 105mm isn't the sharpest lens in the Canon catalog, I'm pleased with the preliminary results.