A principle-based approach
WCAG 2.0 focuses on a principle based approach for all Web delivered content and applications and on core interoperability between assistive technologies and applications. It also removes the absolute restrictions on the use of non-HTML technologies. Instead, WCAG 2.0 offers some criteria for selecting technologies that are accessibility supported and can therefore be relied upon to be supported and enabled in the user's browser and assistive technologies. This approach should enable WCAG 2.0 to be a lasting Web accessibility standard and avoid becoming outdated in the near future. It is inevitable that new Web technologies will continue to be developed. Once they contain sufficient features to allow conformance with WCAG 2.0 and are supported by assistive technologies, then they are considered accessibility supported Web technologies and can be relied upon on WCAG 2.0 conforming websites.
Two other key positive features of WCAG 2.0 are the supporting documentation and test criteria. Even though the volume of supporting documentation seems overwhelming at first, the Quick Reference is a convenient tool that most developers will want to use to quickly index into the information that is most relevant to them. Testers and evaluators will be pleased to have documented test criteria for each technique. In a parallel effort, the W3C WAI-ARIA work will produce test suites with lots of source code which may be included in the plethora of techniques already provided.