New roles need to be very well defined. Instructors don't have to try to do online everything they do in class. Discussion forums are there to support participative modes of learning. For instance, task assignment and task rotation are found most appropriate in order for a community of learners to move from asymmetric to more symmetric learning processes. Instructors are finding that a web-based learning environment is quite similar to a classroom discussion, in the sense that it seems most successful when they are able to get students sending messages to each other rather than always back and forth to them.
Instructors spend less time helping students - they help one another.
They're quick to respond to questions in the HELP section. Those who are not familiar with online conferences learn by doing. Some students don't pay attention to them, but this is particular to online learning activities. Not only are we all struggling with learning the virtual-environment but some do not have basic computer skills. The first part of the course is definitely devoted to becoming comfortable with those aspects.