Are the serial numbers for all of the iterations of the D800 series sequential, or do D800 and D800E have a separate set of numbers. I just received my new D800E and it appears to have a serial number that may fall in the range of units which might have the left focus issue. I will obviously check for focus problems with my particular unit, but am curious as to whether there are two sets of numbers for the different models.
The serial numbers for the D800 and D800E are separate. Since Nikon sells far more D800 than they sell D800E, the D800 serial number is far ahead of the E version. We don't know for sure when the 800E serial numbers crossed into the safe to buy zone, while for the D800 that number in the US is widely believed to be in 3055xxx range. That means a serial number of 3012xxx might be OK for the D800E because it indicates a relatively recent production unit but not for the D800, where that number might represent a very early unit. This is just my opinion based on reading online Forums, I could be wrong though.
I may be misunderstanding your question, but the D800E production and serial numbers are a subset of the D800. Typically the current D800E models have much lower serial numbers than current D800 models. It appears to me that they pull batches of D800's from a production line and modify them with D800E sensor assembly. My D800E was serial number 500 and in the initial batch released - nearly 3 months after the initial batch of the D800 was released. Of course, mine had the AF issue but it was repaired by Nikon at no charge.
I'm not sure what the timing was on resolving the left AF issue. The AF issue affected both models.
The AF problem is easy to test. I shot a series of 10 images with the center, far left and far right sensors using my 24-70 lens at 50mm and f/2.8. Then I shot three frames with Live View AF for each of the sensors. The center sensor was perfect on all frames, the right sensor was slightly softer but still normal, and the far left sensor was significantly soft on every frame with normal focus but sharp with Live View. I used the camera another 8 months before sending it for repair at the end of my warranty.