Cost vs return
I am fully in support of good standards to improve website accessibility. The problem is as it always was, namely that browser companies either interpret ambiguous parts of the standards differently, or choose not to bother implementing those parts at all.
In my opinion, trying to get a website compliant with XHTML, CSS and WAI Level 2 standards, while supporting Firefox 2, IE6 and IE7 and Safari is not impossible, but either places limitations on how it looks or makes it too cost-prohibitive to achieve and maintain thereafter. As a consequence, I would venture that most organisations choose to be "close enough" to the standards.
Even when organisations run the risk of fines for non-compliance, there remains the risk-cost analysis: is it cheaper to take the hit on the fine than to pay web developers to avoid the fine?
One way to resolve all this would be for W3C to take the following steps: remove ambiguity from the standards, and enforce compliance with the browser vendors through. Sure, it's clearly not that simple, but I would argue there is no compelling incentive for browser vendors to comply.
What do other people think?