With all the different options in Vista it's not that hard so customize it to make your PC run better.. There are several different versions capable of different functions. If your system is starving for ram, and is slow, turn off some of the animations, and special junk features like the gadget toolbar, and thimbnails and that hind of stuff that looks nice, but eats up all your memory.. Or upgrade your computers..
Although I did it, its not really something I would have done if I didnt have to, most all new software is going to require Vista soon.. However, With So many companies using XP since NT is no more, I would imagine that Microsoft will support XP a little longer than we all think.
I had to downgrade my system because my laptop got smoked in a thunderstorm, and a critical piece of business software was not vista compatable...of course NOW there is an Upgrade.. That I got for FREE... Now I could run Vista.. that figures huh??