Better control over searches would be good. If the first row of the results pane could be search entry boxes (as in Filemaker Pro), this would save screen space and allow the user to set which terms (like size, kind and bitrate) to use, depending on the columns chosen to display search results
Are 'NOT', '>', '<' terms/character likely?

btw--LW is returning search results that seem to be matching path info or perhaps package contents. (a search for "LimeWire" should show this)