Well I have to say a big thank you to Plymouthbreezer for this thread - it's exactly what I need to snap me out of the thought cycle I've been going through the last couple of days!
I've got a D70s and love it. And I've just invested in a 50mm f1.4 and the 18-200mm VR lenses and the SB-400 flash... which all got me to thinking about the D80. I mean, 11-point focus, ISO100, ability to have a battery grip without the need for external cabling, bigger LCD with a better menu system (apparantly) and the sensor from a D200.... but at the cost of a slightly smaller frame and slower flash sync speeds. Oh, and the shift to SD, which is a pro and con - slower and smaller, but it would mean I can use the memory card reader in my expresscard slot in my MBP, and interchange the cards with my compact camera when needed.
The major aspect was the size to me. The D70s is perfectly sized for my hands. Anything smaller and it feels cramped... and the D80 really was borderline. But I went to go and try one out again yesterday, and thought I could live with it, especially if I got the battery grip. But...
I LOVE my D70s. I know the controls completely, I can change the manual settings like lightening now and it feels like part of me. So after a bit of soul searching - and this thread - I'll be sticking with the D70s. If the D90 (or whatever its going to be) is bigger than the D80, I'll upgrade then, if not I'll wait until my skills are a match for the D200.
So thanks folks - the D70s is sticking with me for a while yet!