The Computer World article links to a recent blog post from Dell. Here's part of that post:
The plan is to continue offering Windows XP on select Dimension and Inspiron systems until later this summer.InfoWorld is sponsoring a petition to encourage Microsoft to continue selling XP beyond the current deadline. Before you sign the petition, you may want to review InfoWorld's privacy statement.
Postal addresses, and other personally identifying information and data will be used to promote InfoWorld and other IDG companies' products and services, and may be rented and/or licensed to selected outside firms for promotional purposes...Also related to Windows XP. Microsoft is scheduled to release the last XP service pack in April. Remember as with any significant software update, wait and watch to validate that there are no significant issues.
Residential telephone numbers of InfoWorld print subscribers registered users are used by InfoWorld to collect re-qualification data and may be used by InfoWorld, IDG and other IDG companies, affiliates and it's advertisers for promotional purposes. InfoWorld may rent and/or license for use phone numbers to selected outside firms for promotional purposes...
Finally, again I would buy now if you're thinking of a new PC, and then wait as long as possible before your next purchase computer purchase. It's very possible by the time you are in the market again that for even the most non-technical folks, you will be able to use Linux or Apple OS within your dominated Windows office and/or friends. If nothing else, while you wait, there is so much help for XP available on the Internet, you should not have any issues getting the required support as required.