I'm fairly certain that N800 was discontinued pretty much at the moment the N810 was released. When that happened the N800 prices plummeted and soon after that they disappeared from the stores. It does make sense to drop the N800 production, because N800 and N810 are quite similar in hardware, but N800 had half the price. It was way too good a deal at the end. This way they can drive the sales of N810 while the software updates keep existing N800 owners happy.

Now I'm waiting for the next IT to come out so I can buy a N810 half free