In 2002 Microsoft introduced its Support Lifecycle policy based on customer feedback to have more transparency and predictability of support for Microsoft products. As per this policy, Microsoft Business and Developer products, including Windows and Office products, receive a minimum of 10 years of support (5 years Mainstream Support and 5 years Extended Support), at the supported service pack level.
Windows XP SP3 and Office 2003 will go out of support on April 8, 2014, if your organization has not started the migration to a modern PC, you are late. Based on historical customer deployment data, the average enterprise deployment can take 18 to 32 months from business case through full deployment. To ensure you remain on supported versions of Windows and Office, you should begin your planning and application testing immediately to ensure you deploy before end of support.
Read what does it mean to you and how Microsoft can help you at http://www.microsoft.com/en-us/windows/endofsupport.aspx?WT.mc_id=MSCOM_EN_US_HP_FEATURE_123LMUS014562
Read my favorites blogs:
Designing a backup less Exchange 2010 Architecture
Step by step guide for upgrading Active Directory from Microsoft Windows 2003 to Microsoft Windows Server 2008
Microsoft Exchange 2010 CAS Array – Steps and Recommendations
Appear Offline in Microsoft Office Communicator Server 2007
Microsoft Exchange 2010 Test cases
Microsoft Exchange Server 2010 Disaster Recovery