The newest version of the edX platform –the October 7th release– introduces private discussion cohorts. This feature allows to create smaller communities of students who communicate and share experiences privately within the larger, course-wide community.
In addition, the CSV file that contains student profile data includes a Cohort column (as long as the cohorts feature is enabled).
Another announcement came from the Engineering blog. The edX-specific version of eXtensible Markup Language (XML) used to format content has been renamed Open Learning XML (OLX), while an alpha version of documentation has been issued.