I have been wondering why more composers do not incorporate any kind of multi-media or web component to their scores. I believe that there is a change coming with regards to this. In no way do I think (or want) printed sheet music to go by the way side. Rather I am just free thinking on what could become additional components to publishing a score
A video tutorial from the composer explaining the piece.
PDF back-ups for printed music
Video of music and score scrolling along at the same time.
A digital composer pack with bio, link to other works and instrumentations
A web site or blog that documents and showcases performers who who performed the work and their interpretation.
MIDI mock-ups. This could include backing tracks in certain instances. (i.e just a piano part for a voice and piano composition, or concerto type works)