As I've posted previously, there's been a great deal of discussion on Windows XP support past June 30, and downgrades from Windows Vista. Thanks to Michael and Mike in the Windows marketing group for pointing out that you can find out more at the facts about the future of Windows XP site.
Provocative name. 😉
There you'll find more info on Windows XP "downgrade rights" and answers to frequently asked questions, such as the often asked, "What'll happen to Windows XP after June 30? I'm confused."
In industry speak, this is called "end-of-sales." On June 30, Microsoft will stop distributing Windows XP as a stand-alone product that you can buy shrink-wrapped in the store. We'll also stop sending it to Dell, HP, Lenovo and all the other major PC manufacturers to sell on their PCs.
That said, Windows XP isn't going to disappear overnight.
You may still see copies of the software—or computers pre-loaded with it—for months, as stores and PC makers work through their inventory. Also, smaller local PC makers—known in the industry as "system builders"—can continue to sell PCs with Windows XP until January 2009.
Finally, Microsoft recently announced that computers with limited hardware capabilities—devices sometimes called Netbooks or ultra-low cost PCs (ULCPC)—can carry Windows XP Home until June 2010. (Read about the ULCPC program on Microsoft Presspass.)
Also of interest: the latest facts on Windows Vista.
In order to see if your PC is ready for Vista, check out the link to the Windows Vista Upgrade Advisor, which can help determine if your Windows XP-based PC can run Windows Vista. We ran this on our PCs at home prior to upgrading to Windows Vista Home Premium with SP1 on most (including a circa 2004 3.0-GHz Intel Pentium 4 with 1GB of memory, and a 1.4GHz Intel Pentium M laptop... both which are running quite nicely). We're also running Windows XP SP3 on the kid's main PC, and I have Windows XP Media Center 2005 still happily chugging away.
Not noted here: the various releases I have installed on machines at work, including Windows Vista Enterprise SP1.