I made a switch-theme module with three drop-down lists of themes -- New, Legacy, and Tiki-bundled. This way it is easy to see the groups. I'll make the list labels links, so people can go directly to pages that explain and list the three types of themes.
I'd like to work out a theme-changing module that would first show a thumbnail preview, responding to a list-item selection, and then the user would click a "select" button to switch to that theme.
Getting fairly well caught up on existing-theme info. Next I want to focus on new themes, finishing the ones I have close to completion so they can be downloaded. And we have to get the theme-upload system worked out so others can share. Plus the promotion of the site.