My D800 I received from BB this Monday, sn 30238xx, appears to not have the LF issue when tested at 24mm with my 24-70 f/2.8. I say "appears", because in very even lighting the LF image (Siemens chart) is equally, and nicely, sharp through the viewfinder and LV. If the lighting was off just a bit (i.e. I used a floor lamp just behind and to the left of the camera, plus decent ambient (1/45 LF meter vs. 1/30 RF meter at f/2.8) I got a fairly blurry LF image through the VF but a very sharp picture through the LV. The RF and center images with the same slightly skewed lighting were both sharp LV and VF.
Interestingly, I discovered a lens back focus issue by testing for the LF issue when I tested the RF spot. RF and center image were both a bit, but equally, soft in LV or VF while the LF image was sharp! With a -7 fine tune adjustment, when focus used the center or RF, the center and RF spot are sharp and with just a tad of softness on the LF image. With the fine tune, the LF image, when focus used the LF spot, is equally "just a tad" soft in VF and LV, and the center and RF are sharp. Overall, that works for me, though I think I need to send in my lens!
Hopes this helps someone.
Oh yeah: I cannot believe the amazing details and overall image IQ after upgrading from my D300s.
Oh yeah 2: You don't need a tripod just because there's 36mp. I'm getting amazingly sharp hand held shots with my 80-400, 70-200 and 24-70. Just amazing.