personality of the instructor in the teaching and learning endeavor. There are actually two interesting strands here, one that deals with the instructor themselves, and one that deals with material creation. I'll tackle the material creation first as I find that this is what piqued my initial interest. Martin Weller writes a little bit about creating materials for the Open University and taking on the role of a member of the content creation team, as opposed to having his own personality. I find this interesting on two counts.
First, in my own online education I have not, prior to starting my doctorate at Athabasca, attended an Open University. Through some of the coursework (namely EDDE 801) I got to see what some of the course packs look like in an Open University setting (assuming that some of the MEd materials shared with us are what a stereotypical course pack looks like). I find the concept intriguing, and to some extent I wish that we could replace readers, or introductory textbooks for as many of our programs as we can with these types of course packs as a way to reduce costs. That said, when course packs are written, I expect that they are written in a neutral tone to not indicate any of the authors personality simply because they will be read by more than just the author's students.
While I am all for author personality in the materials that are created for the course, there is one thing that is nagging in the back of my mind - and this comes from the land of the adjuncts - and that is how little notice some adjuncts get when it comes to them taking on a new course. I know that I wouldn't take on a course where every video or piece of writing started "Hi Class! This is Dr. so-and-so..." because that would mean that I would need to go in and create all new materials for the course for free, and on the fly (which means that you are paid less per course since you sink more hours into it). I think having all material be a-personal is a bit of a problem too, so there is a Goldilocks zone somewhere in the middle where there is some "general" material (assignments, rubrics, syllabi, reading notes, etc.) that don't offer a specific voice, but at the same time there are place for instructors to really add in their own unique voice and subject matter expertise.
Now, as far as the personality of the instructor goes, and it as a factor of success in the course, I think that this exists, and we don't need to look at MOOCs as an example of this. Even with traditional face to face courses I've seen instances where the personality of the instructor has been a make or break element in the experience of the learner in the classroom. Some instructor personalities will not click with certain learners, which will raise barriers (cognitive and affective) for everything else they have to do in that course. And then there are other instructors whose personalities encourage learners to persevere through difficult materials and make it through. Sometimes people actively seek out courses taught by certain people. This, to me, is definitely speaks to the relevance of instructor personality in teaching.
Now as far as rockstar professors go - I am with George Siemens on this, why idolize a rockstar? They tend to do drugs, be late, and not care about others (paraphrasing something he said during a panel at the analytics conference his year)