I vaguely remember seeing something in the news about a lab or school that was using iTunes to organize scientific papers. Well, while sitting through a 'digital resources' seminar, and chiming in to help the library staff help students, that little pathway lit up in my head. I decided to try it, just to check it out.
It does work - you can organize you papers relatively well in iTunes, if you want to manually add the info yourself. That's how it stands as of now, but if you want to be creative, it should be possible to export your bibliographic info to a text file, write a quick script to convert the fields to a playlist (an xml lib file would probably retain all the info), and then import that 'library' into iTunes.
Why would you want to do this? Well, the obvious thing that jumps out at me is smart playlists. Create a smart playlist that uses specific key words or authors, and anytime a pdf is added that meets those criteria, the playlist is automatically updated to include it.
Just throwing it out there. Pic for proof of concept below...