I happened across this article on NPR and found it a bit enlightening.
Harlem Shake on NPR
I also happened across this short video on YouTube.
Some words of caution with this trend....
The words at the beginning of the track "Con los terroristas" translates to with the terrorists.
Since I live and work in area with lots of Latinos, I have also been told that this phrase comes from a Puerto Rican song from a few years ago. I haven't been able to confirm through research the truth behind this but if true, the song that they are referring to is all about gang life.
As with any trend, be careful before including it in a lesson/activity and make sure it has a valid place in your classroom.