SJSU has suspended its Udacity courses because of failure rates from 56-76%. See also Tenured Radical and Edge of the American West.
It's the lesson of MOOC 'n Bake: MOOCs may be great for self-paced learners seeking a tech credential, or those who just want to learn more about a subject, but a substitute for
But evidence-based practices and actual student outcomes have never been a strong suit for MOOC enthusiasts. Quality and student learning are not their concern; efficiency and cost containment are.
As long as someone's willing to lavish grant money on MOOCs, and as there's money to be made by mass producing and "delivering content," MOOCs aren't going away anytime soon.