The Australian government made WCAG 2.0 a mandatory requirement of all government sites. Many claim to conform to the Double-A requirement, but very few bodies do accreditation and the standard itself is almost incomprehensible.
A List Apart did a pretty good article on the issues with WCAG 2.0 in 2006: "To Hell with WCAG 2" http://www.alistapart.com/articles/tohellwithwcag2