Nothing I'm saying applies to the students taking this course for credit. They have a lot of work to cover in a set period of time to meet the standards set in the academic world.
Those of us who are non-credit have set a lower priority bar for ourselves. Don't look at the volume of assigned readings and information being created by course members and decide to stop because you can't carve out that much time. Learn what you can and give yourself an open-ended finishing date. People who create content keep on creating content. Methods of connecting keep evolving. Stephen and George like a mix of new class members and returning class members in the MOOC so if you like the structure of being in a course, you can join in future sessions and concentrate on the things you didn't get to before.
So take a few deep breaths, jump into the water and enjoy this opportunity to connect with people from around with world representing a wide variety of disciplines.