I think the major issue that stores etc do not tell you when you buy a vista machine.
Many of your perphials will not work. Many are not releasing a driver to work with vista - you'll have to upgrade.
Also - i'm curious how many softwares work with vista. How many do not, and which companies will not make the older versions work on it.
I can't imagine having to upgrade the 10 different softwares I use on a daily basis. It would make a new computer cost overwhelming.