ZDNet article on review of XP SP2:

"Security company F-Secure has reverse-engineered SP2, a process the company compares to taking apart a virus or worm to see how it functions, and the company's initial reaction is very positive.

"They have implemented it very well, especially the stack protection and the memory protection. They really did it right this time. We won't be seeing outbreaks like Sasser. It will be hard to attack Windows XP via automated network worms," said Mikko Hyppönen, director of antivirus research at F-Secure."

(Via Claus Juhjl on MS internal blog)