The Media Library was a great addition to Winamp. It allows you to track stats such as last played and number of plays as well as rating tracks.
However the one failing that breaks all this for me is it does not track when a file is renamed or moved – such that if you rename a directory, all details for files that were in that directory are lost.
Tracking a file purely on path is flaky at best, but there are alternatives.
You can’t rely on the CRC or Hash of the file data, because modifying the id3 (metadata) will alter the file, but it is possible to overcome that problem by using a Hash of only the audio-data (ignoring the metadata).
Furthermore as personal computers get more powerful we are also getting closer to achieving personal software that can recognise similar media (graphics, audio, or video).
Graphics software, such as XnView, is already able to do “intelligent” matching of images based on the perceived content. Audio and Video may be more computationally difficult, but it is inevitable that this will become generally available.
When this comes around I look forward to much more intelligent “Media Library” systems, that can actually find your files for you.