I think the module that you have created is quite good, but it needs to be more versatile. What do i mean by versatile? It should give administrators the option to draw articles not only from one category, but also from keywords, titles, and sections. I don't know how it can be done, but i am willing to help. I am not much in to coding for joomla, but my experience in programming should help.
thanks in advance
I did just that in version 3.0.0 you can now use meta keyword from articles to group related items!