Sprungmarker has created the Accessible 1.0 child theme for Twenty 10 that adds basic accessibility improvements to the default theme. The linked site is a demo of the child theme.
I propose that these improvements are merged into the core Twenty Ten theme maintained by the WordPress community and provided with WordPress. Here are some of the advantages I see.
- Adds accessibility features without any negative impact on the theme
- Provides general usability improvements like decent keyboard access and better contrast
- Improves accessibility according to latest W3C standards - e.g WCAG 2.0 and WAI ARIA
- Adding accessibility means more people will have immediate access to more WP instances
- Default theme will provide a useful example of accessibly for new theme developers
- Accessibility is now a legal a requirement, but not so easy to get right
- Other CMSs like Drupal are rapidly improving accessibility features in order to meet this demand
If you need help with a bug/patch I am happy to help out.