I forgot to mention the additional features I want to support n the future.
Most important is allowing search on additional columns besides the full text index. Right now search supports searching on the creation_date of an object (number of days old) and Jeff added search based on the subsite where the containing package is installed.
I think we should support arbitrary additional columns through an optional parameter. I have implemented this for a couple of client projects and it seems to work reasonably well. I think added a callback definition of the additional columns would be approppriate, then the package that needs the additional column support could implement the callback and pass the require query information to the search driver.
One example would be searching an individual forum in the forums package, or underneath a specific sub-folder in file storage or any CR-based package.
Another place I have used this type of feature is searching a package specific category tree.