Thanks for the informative reply, Eric. I don't undestand what you mean when you say the D800E serial numbers are a subset of the D800 numbers with extra production time. Could you elaborate?
A D800 serial number of 3050000 would indicate to me that it is 50,000th unit off the line, but it probably doesn't work that way. The D800E that I received two days ago has a SN of 3008xxx, which no doubt fits into your subset of 3050000 scenario, but I don't quite understand the relationship.