13 July 2010 is the last day that Windows 2000 and Windows XP Service Pack 2 will receive support and patches from Microsoft. Starting tomorrow, Service Pack 3 will be required to receive support and hotfixes for Windows XP.
In the past, the end of support for a service pack would mean that Microsoft would refuse to offer any kind of telephone support or troubleshooting assistance. This policy was relaxed a little in April; limited support will remain available for those organizations sticking with Service Pack 2. However, any hotfixes or security updates will be restricted to Service Pack 3.
Customers on Windows 2000 will not even have this option. The operating system is now out of its extended support phase. This brings an end to any and all hotfixes, security updates, or even paid support options. Fewer than half a percent of Internet-connected machines appear to use Windows 2000, and with the end of support, it is now open season on that minority: Microsoft will take no action to provide fixes for any security issues, regardless of their severity.
Source: ars technica