An alternative point of view, aside from my usual microsoft bashing...
It's not that I wish any ill will on Microsoft as they've done a phenominal job of taking a realtive complex "think" and making it simple enough for just about any intelligence level. And in doing so, they've managed to cash in along the way...
Bravo, and I really mean that...
But, here's where I start disagreeing with them... The sun doesn't shine out of their ass, they don't do things better than everything else and they can only idiot proof things so much before it becomes either a pain in the ass or it's just so bogged down with legalities that a fair portion of its user base gets tired of all the bs and starts looking at Open Source alternatives.
Business isn't necessarily ready for the likes of Vista because of all of the administrative overhead. Also, if I understand correctly, a lot of the really cool policies that could make the lives of IT brethern & sistern so much easier, really aren't available until you get a long horn server up & shipping out GPO's. Which, as I've learned first hand, also applies to XP boxes as well. So, why would any business go through the hassle of deploying Vista if the server infrastructure isn't already available to fully implement it?
Secondly, as far as the home market is concerned... Bill, Steve, what's-his-name... Guys, people are inherently cheap... Unless someone has money burning a hole in their pocket, is even slightly technically inclined and has a whole lot of time on their hands, most people aren't going to be busting down the doors to replace what has now become a relative benchmark standard OS for something brand spanking new, that has lots of "features", "nuances", "idiosyncracies" or is still so new it's just flat out buggy.
Most people have a relatively good understanding that the only truly stable computer is one that's powered off... And no matter how smart the user or business admin is, at some point in time, something is going to go awry. And given Microsoft's declining track record when delivering a product that actually works as promised, is it any wonder that the only way they can sell Vista products is at gun point?
I just purchased two computers for home... a laptop for my wife (that came with vista) and a little after that, a quad core desktop, for myself... After spending I don't know how many hours getting her crap to work on our little home network, when it came to ordering my machine, I just went with XP.