The United Nations commissioned a report on web accessibility with very disappointing results. Only 3 home pages from 100 web sites achieved Single-A accessibility from the WCAG 1.0 guidelines (the lowest level of web accessibility compliance). The sites were chosen from 20 countries in 5 categories (Travel, Finance, Media, Politics, and Retail).
Also, here’s a blog post about the issue along with a lot of discussion at 456 Berea St: 97% of websites are still inaccessible.