Math and (future) CS teacher here (starting a program at my all-girls school next year): Just factually, it's worth noting that AP Computer Science A (the course done by this MOOC and that has been around for many years) and AP Computer Science Principles (the new AP course that code.org, among many others, will offer a curriculum for next year) are designed from the ground up to be wildly different animals.
AP CS A is a traditional programming course that uses Java as its required language. It goes fairly in depth into topics like algorithms and big-O notation and analysis, but is primarily focused on procedural and OO programming skills. It has a 3-hour exam, mostly multiple choice but with a small "hand-write a program to do x" section as well, as its final assessment.
AP CS Principles is designed to be a project-based course covering general topics such as abstraction, data and information, using computers for creative expression, the internet, collaborative problem solving, and the global impact of computing, as well as an introduction to programming. Teachers and students can use any programming language they'd like - early curriculum materials exist that use everything from Scratch to Javascript to Python. The assessment consists of a shorter multiple choice test (any programming examples in the test use a very simple, well-defined pseudo-code, rather than requiring specific language knowledge) AS WELL AS two submitted digital projects: one programming project (with both individual and collaborative components) and one research project on global impact of computing. Like the AP Studio Art projects, rubrics and basic guidelines for these projects are required, and readers will be looking for specific knowledge on topics such as abstraction and algorithms, but the project itself is designed and chosen by the students themselves.
CS Principles is not likely to scale as well to a MOOC (and frankly I have doubts that code.org's implementation will be amazing either). Personally, I'm very excited about the course as we HAVE had a hard time keeping enrollment numbers up for traditional programming courses in my smallish all-girls school - I think this one allows for a little more room for the exploration and creativity that seems to be of more interest to girls.