How close are we?

In the year 201x, somewhere in the University campus:

- Students are invited to RSVP on meetup.com if they are going to attend the class
- Once the class has started, present students should confirm their physical attendance by check-ins on Foursquare for the place called Room 145, University of...
- If the teacher is absent, he can teach remotely by using his avatar for live presentation
- If some students are absent, they are free to attend the class online on the Facebook group
- The lesson is composed by tweets. At the end, the Q&As session is held on Quora.
- Students chat between themselves during the class on Facebook, posting on each other's walls and commenting

The challenge is, define x! :)