It's not the pixel density but the angular pixel density that determines susceptibility to shake. The D800 has 100 pixels per degree, the D7000 only 67. However, down-rezing the D800 file to 16MP in theory should more than compensate for this. In practice, it's never quite that simple. The actual characteristics of the blur, including contrast, come into play. I think we're just going to have to wait and see.