With the release of the final service pack for Microsoft Windows XP, and the coming end of retail availability and Microsoft support for Windows XP, it might help to keep the following dates in mind as you think about upgrading to Windows Vista.
First, Windows XP Service Pack 3 (SP3) is available now through Microsoft's Windows Update for single computers or as a standalone download for IT staff in a networked environment. Free support for issues arising from installation of XP SP3 is available from Microsoft through April 14, 2009.
Here's the timeline:
June 30, 2008: end of retail availability. Microsoft will no longer offer Windows XP through retail outlets. Manufacturers such as Dell can continue to install Windows XP Professional at a customer's request under "downgrade rights" for purchasers of Windows Vista until their inventory of Windows XP Professional is exhausted. This applies only to purchases of Vista Ultimate and Vista Business versions, and allows a downgrade only to XP Professional, not XP Home.
January 31, 2008: Microsoft will no longer sell Windows XP to original equipment manufacturers.
April 14, 2009: end of free support for XP. Microsoft will continue to provide security updates through 2014, but product support for customers without Microsoft support contracts will be charged at prevailing rates (currently $259 per incident for live support, or $99 for email support).
April 8, 2014: All support for XP ends.
The bottom line: Vista is inevitable, and with Service Pack 1 now available, the sooner you make the change, the more you'll get from your investment. (Put it on your list of upgrades along with the need to buy a digital television or set-top converter box by 2009.) There are many tools available to help you figure out whether your current computer and peripherals will work well enough with Vista and how to learn Vista. Check out the links to Microsoft Vista pages on TechInfusion's web site for a handy collection of Vista resources; I don't usually mention TechInfusion in my blog, but you'll find that these pages will save you time searching Microsoft's site, and will provide you with information on new topics you might have missed.