From: "Peter Wiggin" <peter@oreilly.com>

From a user's point of view, we need to consider if and how the W3C
might test whether implementations of W3C standards are actually
valid.  If, as we have with Microsoft, the standard and the dominant
implementation diverge, then what is the real standard?

The W3C should arguably either amend its standards or use its weight to
press for change until the vendor comes into compliance.

Another point close to my heart is the XHTML question: yes, XHTML is
the new W3C standard for HTML, but what are the benefits of compliance
on the user end? In a few cases, there are actually new problems that
arise as a consequence of making your pages XHTML compliant, so why
would a designer/author want to make their pages XHTML compliant?