Really it is quite different, and I think people saying it's the same for Vista as it was back then either weren't using computers back then or have forgotten. At the office it may have been somewhat similar but then again people using 2000 at the office probabably didn't upgrade from 2000 to xp. The client upgrades at the office I saw back then were 95/98 to XP. Regardless XP was big with the home users, there were lines to get XP when it was released, I got mine the day of release there was a lot of buzz in the air. Yes there were hardware compatability issues, I remember people complaining about it, However... here are some things that are substantially different
1) There were no real lines to get Vista, at least not where I live
2) There was no real buzz in the air
3) Despite hardware compatability issues, XPs performance was still pretty good, Vista performance is much lower on the same hardware
4) The only thing home users really got in return for the performance tradeoff is a snazzy new interface... and if you are reading this you already know you can get that with good performance on XP using windowblinds. XP was a much bigger upgrade for people using 95/98. The majority of people I know skipped ME all together.(much like what could happen with Vista)
5) Most hardware issues for XP were driver related, Vista often requires new hardware not just new drivers.
6) People having problems after upgrading to XP complained alot too, however... compared to any OS release to date that I can remember(DOS was my first OS), I have never seen so many people downgrade back to XP after upgrading to Vista. I know a lot of home users who have it done it, and I know several companies who have and are doing it.
I do think for most companies it is only a matter of time before they switch clients to Vista, and it may coincide with server upgrades to 2008, but for many companies it is an expensive proposition because it is often not only a software upgrade that is required. Home users are a different story, Windows 98 got skipped by quite a few 95 users, ME got skipped by damn near everybody I know... I have a feeling Vista probably will do better than ME, but I doubt it will get the percentage of upgrades that Windows 98 or XP got.
The numbers Microsoft shows you is a simple count of licenses sold and OEMs greatly distort this number, it definately doesn't show how many people are actually using the OS. Granted on this site you probably have a higher percentage of people using Vista than the norm since people here are often more intrested in looks than functionality(not intended as an insult, I fall into this category myself)
I'm not saying Vista is bad, it just isn't doesn't have much to offer the home user(especially if you already are a windowblinds user) and distorting history is not going to encourage more people to buy it.