This is not a revolution!  IRC is similar in many ways to conventional class discussion, but
also has distinct benefits.

decenters the classroom, thereby encouraging active learning
connects readings to writing to develop literacy
connects writing and thinking to encourage critical thinking
encourages participation from students not active in traditional classrooms
easily adapted to different teaching or discussion styles
may enhance participation in the traditional classroom
allows instructor to monitor multiple student discussions
archives discussions which may be used for review, reflection, assessment, etc.