Category as group key

Hey there. I'd like to theme related content using categories. Ideally, my related content template will be able to query the $output param by a vocabulary-term tuple. So my template has knowledge of what vocabulary and terms to ask for, and the $output provides a map to the related nodes for those respective categories. Hope that makes sense.

The use case is a newsletter that has regular, well-defined category sections.

My current plan is the hack the heck out of the related content module. I'm learning drupal and php as I go, so you can imagine how pretty this is going to be! :-)

My initial plea, is for advice on how to hack it.

Building this into the relatedcontent distro would be extra credit. Happy to contribute if I can. Maybe you can give me a suggested design. I'll go prototype it. And then you can decide if it's worthy to be part of the module?

Thanks,
-Tim