Ironically, if he has left to concentrate on Udacity, my own belief is that he is a poor teacher. Of course it depends on which pedagogical teat you are sucking from, but my experience of Thrun's delivered Udacity courses is poor. Many of his video segments seem to involve him slavishly following his 'script', occasionally hissing out encouraging phrases such as 'Isn't this great!'. He hasn't sequenced a series of logical teaching moments in which the concepts flow nicely. It's as if he's decided his first draft is good enough. Just my opinion of course.