WP theming

• HTML5
• Responsive
• Grid
• Accessability

Base themes

• Bones - A Mobile-First, Responsive WordPress starter theme based off 320 and Up & HTML5 Boilerplate.
  • https://github.com/eddiemachado/bones - very recent

• http://demos.simplethemes.com/skeleton/- "Skeleton is a simple, responsive WordPress theme based on the Skeleton Boilerplate. It has several useful shortcodes, such as tabs, toggles, cross-browser CSS3 buttons, and layout columns. It also includes a bbPress skin/stylesheet and sample child theme. "
  • https://github.com/simplethemes/skeleton_wp - recent

• http://themefortress.com/reverie/ - "Reverie Framework is an extremely versatile HTML5 WordPress framework based on ZURB's Foundation, a powerful tool for building prototypes on any kind of devices. Reverie follows HTML5 Boilerplate standard and is hNews microformat ready. It is optimized for Search Engine while at the same time improve readability."
  • https://github.com/milohuang/reverie - kinda recent

• http://whiteboardframework.com/ - HTML5, responsive, Less
  • https://github.com/johanbrook/whiteboard - Jul 17, 2011

• https://github.com/scottlyttle/Sass-WordPress-Reset-Theme - Sass, Modernizer, jQuery, form components
  • https://github.com/scottlyttle/Sass-WordPress-Reset-Theme/blob/master/SCSS/style.scss

• http://html5reset.org/#wordpress - jQuery, Modernizr, hNews Microformat and Analytics
  • https://github.com/murtaugh/HTML5-Reset-Wordpress-Theme - year ago

• http://randyjensenonline.com/thoughts/handcrafted-wp-starter-theme/ - HTML5 [Boilerplate], jQuery

• https://github.com/nathanstaines/starkers-html5 - HTML5, bare-bones

• http://designwoop.com/2012/01/wordpress-html5-frameworks/

Social

• http://themeforest.net/
• http://activeden.net/