Service Pack 3 will contain all previously released Windows XP updates, including security updates, out-of-band releases, and hotfixes. SP3 will also feature four Vista features.
- Network Access Protection (NAP) is a policy enforcement platform meant for enterprise use that blocks systems attempting to access a network until they meet whatever security criteria the corporation has in place.
- "Black Hole" Router Detection helps detect and protect end users from a router that drops packets without returning the specified Internet Control Message Protocol response.
- Microsoft Kernel Cryptographic Module incorporates cryptographic algorithms in a single module other kernel mode drivers are capable of hooking into and accessing.
- The new Product Activation module allows users to install XP without entering a product key at installation.
Windows XP Service Pack 3 Overview (in pdf)