This is exclusive info straight from the site: www.inuyasha_movie.com.
The 4th InuYasha movie, called InuYasha: Guren no Horaijima (or Crimson Horai Island) is schedualed for a release in Japan on December 23rd, 2004. It will feature voices from the Japanese band Do As Infinity, as well as music from the same band.
It is rumored that at least ONE main character DIES in this movie (and its SUPPOSEDLY either Miroku or Sesshomaru)
Submitted by Mitsune