OK I want to be the second client to request this functionality.
My client wants the option to be able to select muliple categores to filter the results on.
At the moment I see no way to find all files that have been tagged with Category A and Category B.
There might even need to be a seperate search for Category search that just displays the Category List with checkboxes. Then the user could search for as many Category combinations as they want ( include the option for OR and AND).
Your module is the 90% solution at this point, and this feature would take it to the 100% solution.