Coursera continues to make headlines as additional "top tier" universities sign up to offer courses (16 institutions and 116 courses, at latest count), and hundreds of thousands of students sign up to take those courses. MITx, on the other hand, has not gotten much coverage lately, especially since the creation of EDx. MITx is moving much more deliberately, of course, with only one course up at this point (3 more announced for the Fall of 2012), so we know much less about how MITx will actually look and feel than we do about Coursera. However, Coursera and MITx seem potentially to represent very different approaches to the expansion of online learning, and those differences may be very important in determining the ultimate impact on higher education of online learning. In this post, I will explore some of those differences as I see them, and their potential implications.