Here something important (and perhaps obvious) that I've learned from taking online courses and from teaching a blended course:
It's just like a traditional course in this way: A majority of students will put in a minimum amount of effort unless the assignment/reading/discussion is graded. When one of my professors has an "optional" discussion or assignment, only a handful of students participate. We are all focused on the many assignments and readings that are graded and often don't have (or take) the time for "extra" work. With respect to this blended class, many "students" want to get whatever is easy and comfortable--like coming to the F2F sessions but don't want to put out the effort necessary to do the online part of the course. The lesson for us is that we must think very carefully about the incentives we provide for our E and P students in the new blended programs to make sure they stay involved and engaged in the course between the F2F sessions. The assignments and discussions must be meaningful and necessary for success in the course. For this blended course (Blend 101), anything that those who are taking the course can learn from the experience is a plus. For our MBA programs, engaging the students is not optional. It is critical to the success of our programs.