I was an early adopter for XP and wrestled with bad drivers, bugs and incompatibilities in the first year. I was happy with the release of SP1 when the OS became more stable as the drivers continued to evolve. I moved on to XP x64 shortly after SP2 was released for it in May, 2007. The release of Vista x64 later that year improved driver quality and driver availability for XP x64 considerably as hardware vendors finally started to pay real attention to x64.
Vista may have stabilized by now, but I don't like many of the UI changes made. Win7 is still in its infancy. And the DRM foisted upon both borders on unacceptable. I won't be moving from XP x64 any time soon.
As Microsoft releases the updates, so shall I release the update packs—for as long as I'm able, anyway.