Windows 7 will almost certainly replace Windows Vista before folks can stop buying Windows XP, or even getting official support of it. At that time, Windows Vista as a nomiker will completely vanish. It will, in many ways, be as if Vista never existed. They will push upgrade from "your old Windows" or "Windows XP" or "all previous version of Windows" but Windows 7 will be as distant from Windows Vista as possible.
And it's not because Windows Vista sucks. It doesn't. It's a pretty solid operating system, with problems no different than you might expect from an operating system that has to run in seriously heterogeneous environments, and was going to have to run on something like 100 million more desktops and laptops than when Windows XP shipped.
And if you think Vista has problems, do you remember when Windows XP first came out? Vista actually got a lot more right, right out of the box, than XP did. Or, for that matter, Windows 95, but Microsoft marketed the heck out of Windows 95, in a very positive, cool product launch sort of way. Given Microsoft's current too-little, too late marketing strategy, apparently those people must not work at Microsoft anymore.
The problem is, Microsoft mismanaged and mis-marketed (i.e., did no real product launch marketing for Windows Vista), and it shows. Their current ads and the Mojave experiment really didn't do them any favors. Windows Vista has become synonymous with "buggy" and "insecure", even though that isn't fair.
Without Windows 7, expect them to barely mention Windows Vista again. And, if they're smart, they'll roll it out with a splashy product launch, lots of commercials (that don't acknowledge that the Macintosh exists, BTW) and celebrity endorsements and appearances on Jay Leno and David Letterman. Or they'll do something stupid and incomprehensible, and leave the hyper-critical blogosphere to define their new product. That would be really smart.
More Windows 7 News Here. And, Windows 7 is Going to Support MultiTouch. Now, that actualy makes that technology useful.
Also, just to remind you, we've got Microsoft Windows 2000 Professional Full Version OEM for only $92.33, or $89.99 each if you purchase 25 or more. Handy if you want to stay compatible.