Okay, I've been playing with mine today and there is definitely something going on with the in camera jpges. I shot in RAW + JPEG today to compare and found all the jpegs to look very muddy as far as detail. As a basis for comparison, I opened the raw in DPP and set it to Neutral, no sharpening, no ALO, no noise reduction and exported a 16-bit TIFF. I then imported that TIFF into Aperture and did a version with sharpening and a version with Niks ColorEfex Tonal Contrast (which does bring out detail). Here are 100% crops saved as jpegs. The neutral TIFF shows more detail than the in camera JPEG. The Aperture sharpened TIFF looks best. The Niks contrast enhanced TIFF looks pretty good too. I suspect a combination of sharpening and the Niks filter applied more subtly would look even better, but I didn't try that.
At this point I am wondering if this is less a sensor issue and more an issue with rushed RAW processing software.