Purchased and ran OEM's of Vista Home Premium on both personal machines (1 DIY desktop, and 1 Dell notebook). Although I really enjoy the icons, address bar navigation, ease of networking, and the idea behind the new Windows Driver Display Model - I nevertheless have reverted back to XP Pro on both machines for the following reasons:
1 - Adobe CS2 runs much better on XP Pro at this time.
2 - The ATI drivers are still in their infancy and are basically just 'vanilla' drivers.
3 - Nero 6 just works on XP Pro and I am not excited about all the extras in Nero 7 - especially the fact that 'Nero Scout' is not offered as an optional install on the downloaded version (not sure about the CD version).
4 - The search functionality, multimedia functions, and Tablet PC functions all increase the process count to the point that my poor Dell notebook with a single-core 760 processor has it's hands full just trying to run the OS. Turning off some of the Tablet PC functions is possible so that a Wacom tablet driver will only run 2 or 3 processes, but stopping the search and multimedia processes just defeats the whole idea of a Vista upgrade.
All in all, I have to say that Vista is exactly what I expected; a new operating system that has a lot of potential for use with hardware that has yet to be released (or is currently on the 'bleeding edge'). I think the need for a multi-core processor is absolute if you want to run 45 - 60 processes in the background and still enjoy efficient use of the installed programs. I look forward to next year when a good DX10 video card can be purchased for a reasonable price and will be supported by stable drivers with good control options. This should also give me time to save enough to invest in Adobe's CS3 package.
Of course, I may just decide to go with the Mac platform by that time. 
