The W3C posted an update to the Relationship between Mobile Web Best Practices (MWBP) and Web Content Accessibility Guidelines (WCAG), something which I (for some reason) don't remember seeing go by in January when they posted the initial draft.
Work like this means a great deal to web developers who promote accessibility, as most people regard accessibility as little more than a drain or a checkbox on a compliance to-do list. The MWBP and WCAG relationship guidelines look at the similarities in issues and solutions found in each working group, providing a comprehensive list of direct connections between accessibility and usability. Until seeing this work, I have had little reference material to offer those who questioned my (and others') relentless insisting that they should use accessible markup and scripting in order to make their web applications both accessible and more usable in one fell swoop. All efforts had previously resulted in spontaneous lectures at the nearest machine where I could demonstrate examples, and (more recently) Chapter 1: Usability and Chapter 2: Accessibility in Advanced Ajax: Architectures and Best Practices.
The current MWBP and WCAG relationship guidelines have the following in-progress sections available, which will all prove exceedingly useful to web developers and designers, especially for those learning about one side of this after implementing the other:
These sections cover specific examples of matching mobile web
usability issues with accessibility issues, ranging from color contrast
..unfavorable ambient light and the ability of
devices to display contrasting color at all, while users may have color
blindness and color perception deficits...) to the fact that large
amounts of dry text becomes equally unreadable for those with attention
deficit related disabilities to those with postage stamp-sized screen.
Anyone who had clicked impatiently through an EULA displayed in a one-inch
textarea knows the latter of these two quick examples all too well.
For a quick introduction to the correlation between web accessibility mobile web usability, the WAI has posted Web Content Accessibility and Mobile Web: Making a Web Site Accessible Both for People with Disabilities and for Mobile Devices as part of their Implementation Plan for Web Accessibility.