Just because Vista will be the latest Windows operating system doesn’t mean that everybody will run out and upgrade. For one, it’s expensive. Secondly, some people simply don’t like change. Upgrading to the latest operating system is last on their list, especially if they’re still getting used to XP. There are a variety of reasons that users won’t instantly make the upgrade Vista. This has left some wondering how long Microsoft will provide support for XP.
Originally, XP Professional was going to have support through April, 2014. XP Home Edition however was originally said to have support until April, 2011. Just yesterday, Microsoft announced that support has been extended for XP Home Edition, as well as XP Media Center edition.
Now XP Home, Media Center, and Professional Editions will all be in-line with each other. Microsoft will offer five years of mainstream support (until April 2009), and an additional five years of extended support which will take it to April 2014. It’s hard to believe that people would still be using Windows XP ten years from now, but it’s very possible.
Also keep in mind that Microsoft is still planning on a service pack three for Windows XP, is expected for release in 2008. There have been rumored features including WinFS (Windows Future Storage), and a user interface updated with a more powerful sidebar.

In the article here on Cybernet that you link to, it says Fiji is an update for Vista, not XP.
Additionally, the article on Wikipedia about Fiji has been deleted, with the reason for deletion page mentioning the rumor of Fiji is false.
[en.wikipedia.org]
Oops, my mistake. Thanks for pointing it out.
Looks like she just fixed it…happens to the best of us.
Well, I think Fiji is real but there probably wasn’t enough accurate information for a Wikipedia article on it. It is inevitable that there will be a SP1 for Vista it’s just whether the codename is Fiji. Even Paul Thurrott, who has a lot of inside sources, [winsupersite.com] saying “Windows Vista Service Pack 1 (SP1, codenamed “Fiji”) is due in late 2007 alongside Windows Longhorn Server, as is the next version of Windows Media Center, though Microsoft is still not sure how they’ll ship that latter upgrade.”