Damien,
Nikon make some very nice stuff indeed, as proven by my now 17 year old F801s, which, up until a few months back, was still being used to shoot a fair bit of work stuff. By my estimates, I've shot over 1,000 rolls of film on it (no idea for previous owner, but would have been through a few), and it hasn't missed a beat. The F90x is the same, albeit only about 400 rolls. I'm assuming you're happy with the 5000 - I have seen some real nice stuff from those bad boys!
The wait for the D200 is not due to new technology so much as a more durable build quality (has magnisium chasis and gasketted etc.) Indeed, from the specs, the technology and end results from both are fantastic.
I'm just wondering whether I need the extra durability (as I'm no longer shooting on a very regular basis (ie, daily) and whether a D70s would suffice.
Newflyer