Here's a great article on making accessible WordPress themes, including the authors own theme. The article is titled Surprise! Your "semantic, accessible, search engine friendly" WordPress theme is none of the above.

www.bushidodesigns.net/blog/semantic-accessible-seo-friendly-wordpress-theme/

In addition to the theme, the article provides good insite into making a web site/WordPress blog accessible.

I like the theme, but although it's a bit bare. Adding a bit of color and it looks great.