SP2 unlocks Athlon 64 buffer overrun protection
C|Net has confirmed that Athlon 64 and Opteron owners will get a little security bonus with Windows XP Service Pack 2. SP2 will reportedly activate a dormant feature in AMD's 64-bit CPUs that helps to protect against buffer overrun exploits:
AMD's Athlon 64 and Opteron security features will work with Windows XP Service Pack 2's Data Execution Prevention feature to prevent buffer overrun exploits, a common method used to attack computers. A buffer overrun or overflow essentially overwhelms a computer's defense systems and then inserts a malicious program in memory that the processor subsequently executes
As if the Athlon 64 and Opteron weren't sweet enough processors already.
The article doesn't mention whether the overrun protection technology will work with operating systems other than Windows XP, though it's interesting to note that the feature will be "turned on" when SP2 is released. Since even Linux is vulnerable to buffer overrun exploits, it would be great if AMD's technology worked with any operating system.