The entire season is dedicated to the memory of Kim Manners, who passed away January 25, 2009 from lung cancer.
When Sam and Dean first encounter Cole's spirit, Sam tries to tell Cole that he is dead, to which Cole replies "Yeah, I know that, Haley Joel." This is a clear reference to The Sixth Sense (1999), which starred Haley Joel Osment as a kid who could communicate with ghosts. Coincidentally, his character's name was also Cole.
Pamela refers to Dean as Chachi, Chachi was Arthur Fonzarelli's vapid but handsome cousin on Happy Days (1974).
Jared Padalecki, Jensen Ackles and Alexander Gould have all played the 'sons' of 'Jeffery Dean Morgan'. Jared and Jensen in Supernatural, and Alexander in the show Weeds (2005).
This is the second episode in the season to reference The Outsiders. Pamela says she does not want to get mixed up in their "Angel/Demon, Soc/Greaser battle". In the episode titled After School Special (2009) The Outsiders is written on the chalkboard of young Sam's classroom.