Microsoft will end all support for Windows XP on 8 April 2014

Windows XP SP3 and Office 2003

Support Ends April 8, 2014

It means you should take action. After April 8, 2014, there will be no new security updates, non-security hotfixes, free or paid assisted support options or online technical content updates.
Running Windows XP SP3 and Office 2003 in your environment after their end of support date may expose your company to potential risks, such as:

• Security & Compliance Risks: Unsupported and unpatched environments are vulnerable to security risks. This may result in an officially recognized control failure by an internal or external audit body, leading to suspension of certifications, and/or public notification of the organization’s inability to maintain its systems and customer information.
• Lack of Independent Software Vendor (ISV) & Hardware Manufacturers support: A recent industry report from Gartner Research suggests "many independent software vendors (ISVs) are unlikely to support new versions of applications on Windows XP in 2011; in 2012, it will become common." And it may stifle access to hardware innovation: Gartner Research further notes that in 2012, most PC hardware manufacturers will stop supporting Windows XP on the majority of their new PC models.

More info at Microsoft site