[wp-hackers] Templating Ideas

[Cristiana Yambo]

I wanted to expand the templating engine with this idea I have.     
Whenever there is a place where WordPress is generating a piece of  
content, such as with wp_list_cats, you can add a class name to the  
parameter list, so each category will  belong to the class you  
specified.

Is this something that can be a module, or is this something that has  
to be done to the main branch of wordpress, also is this a good idea?
cristiana