I have had my N800 for only about 6 months now. I kept hearing about how the N810 and it's keyboard worked so much better than what I had. I was very tempted to sell my N800, BUT, I found a deal on a bluetooth keyboard here in the forums. Having that keyboard brought new life back into my N800. I don't think I will be giving this thing up for a while.
At the moment I'm booting from SD Card (8GB). I've installed Easy Debian and am looking to expand the partition size for it (install apps). My external SD card is a 16GB Card that easily holds most of my favorite music with room to spare for a movie or two in case I'm going on a trip. Then again, I have 2 thumb drives which hold 8GB each. I connect those through my USB adapter to my N800.
Like I said, I'm very much happy with the setup I have now and don't even think I would consider a new Nokia when it comes out.
.. At least not for the first couple of months.