The United States Access Board is currently updating the Section 508 standards. Its motivation is very sound. Technology that changes with a blink of an eye, products that overlap each other, international standards that need to be applied conjointly, and a perpetual call for a positive economic impact are behind the Section 508 Refresh, which is expected to be released the first quarter of 2014.
Section 508 Posts
It's no accident that both Section 508, 1194.21(c), and WCAG 2.0 Success Criterion 2.4.7 both call for visible focus indication. Users with mobility/dexterity disabilities often rely on keyboard accessibility, perhaps using assistive technologies (such as mouth sticks) that rely on the keyboard.