Check out the WordPress codex page for Theme Frameworks that “ease theme development by reducing the volume of work which may be needed in creating a backbone for your theme”. Thematic is mentioned along with The Sandbox and others.
Cozmos Labs has a great tutorial showing how to replace the default Thematic menu with a dropdown list of categories. Included with the tutorial is a free Child Theme, CatDrop, perfect for those of you interested in making Thematic more like a magazine-style theme or wanting to see how to make a dropdown menu work.
Nathan Rice has good advice on how to optimize your WordPress Meta descriptions and take more control over how your blog appears in search results.
Andrew Rickmann demonstrates how to create custom content types in WordPress—and creates a WordPress Twitter clone in the process. Amazing. Anyone using WordPress as a CMS needs to read this post.
WordPress developer Jacob Santos on WordPress Child Themes: WordPress Theme Modifications should be made in Child Themes.
If you want more of an introduction to theming your blog or website with WordPress Child Themes you can read my two-part interview with Weblog Tool Collections’ Jeff Chandler on the subject. Part One gives an introduction to the concept with a ridiculously easy tutorial that guides you through making your own Child Theme. Part Two goes through some of the business implications of using them with a WordPress Theme Framework.
Pat Dryburgh outlines the drawbacks to child themes—which hinder public acceptance and experimentation—that he’s discovered while working with Thematic.
Darren Hoyt explains why he’s interested in WordPress Child Themes in Exploring WordPress Frameworks and Child Themes. He does a great job illustrating why professional designers using WordPress to power sites need to take a serious look at them.