As an administrator for a small county government i'm a bit skeptical when it comes to Vista. I've played with the OS in my lab and found it to be a burden with all the nagging screen pops. Most of my time spent with Vista was spent trying to make it look like XP. My users tend to be older and rather particular as to how their computer reacts to any given situation. So, switching to Vista would send most of them directly to their phones seeking my help to restore their happy little bubbled existence. Not to mention that half or more of our software vendors will not support their product when installed on Vista.
So for now i'll continue buying new computers with Vista licensing only to turn around and have XP installed for production.
I'm not sure if i'm more disappointed in my vendor for their lack of software support or in Microsoft for not releasing XP sp3. Sigh...