NeoSmart took a look at Windows XP SP3 Beta Build 3205. The site reports this new service pack doesn't only pack patches and hotfixes but also a couple of new features:
New Windows Product Activation model: no need to enter product key during setup. Thank God for that!
Network Access Protection modules and policies have been brought to XP after being one of the more-well-received features in Windows Vista. You can read more about NAP here.
New Microsoft Kernel Mode Cryptographic Module - the Windows XP SP3 kernel now includes an entire module that provides easy access to multiple cryptographic algorithms and is available for use in kernel-mode drivers and services.
New “Black Hole Router” detection - Windows XP SP3 can detect and protect against rogue routers that are discarding data.