Multimedia is interesting! Compelling! People like using it! Students learn from it! It works! Anyone can develop a package; just point and click!
The truth is that many things are simpler, cheaper, quicker, and -- gasp -- more effective. Multimedia really can draw a student's interest, but like any movie or class, it can also be boring. Once the novelty wears off, the merit of multimedia will be based on its content, presentation, and effectiveness.