Hi Sarah,
I have mixed feelings about whether Social Media will be more focused on the 'Social' aspect rather than the 'Subject' at-hand.
Especially working with teens and early college students, personal comments with photos rather than factual & informational comments may cause distraction from truly understanding the topic or retaining the topic.
Possibly if no photos of students and a concise or micro-blogging, students may still be gaining insight into the content the instructor is desiring her students to ponder.
Time will tell if Social Media will have a stronger presence in our online classes in the future! Lee Russell