Problem/Motivation
It's (almost?) impossible for themers to display the forum topic list as anything other than a table. Even if you create a custom template_preprocess_forum override, and add a new template for the forum topics, you can't do much with it because the topics data is structured to be passed to the table template with a header and rows.
Proposed resolution
The template_preprocess_forum variables array should include the original topics data, so themers have an option to display it differently.
Remaining tasks
- Create Change Record