I found an infographic on how professors use social media. Two points seem worth mentioning here: the social networking gap between students and professors is shrinking and professors in the humanities use social networking the most for pedagogical purposes, which could include blogs, wikis, and podcasts.
I have reproduced the graphic below, but the whole story can be found here.
Is it important that the gap is closing? Do students think it is important, helpful and/or beneficial to have social networking and other web 2.0 experiences integrated into the course?