Microsoft happened to earlier state that their support for Windows XP and its Media Center-version would end the 31st December 2006. This would have resulted in that people who bought a computer in October would end up without downloads such as security updates and more for their operative system two months later. Luckily, it only was an error by Microsoft themselves; they will keep releasing patches and updates for XP Home until 2008. XP Professional though, will have an additional five years of support, since it’s a product meant for companies. We knew that that Service Pack 3 will be released somewhere during the release of Windows Vista, so anything different from this would be quite surprising.
Source: Firingsquad