House (Hugh Laurie) refers to a "cunning plan," a catchphrase from the Blackadder series, which co-stars a much younger Hugh Laurie prominently in series 3 and 4.
House asks what floats, the answer being a duck. This scene references Monty Python and The Holy Grail, when tests are performed to prove someone is or is not a witch.
According to the title of the episode, it refers to a phrase attributed to Marie Antoinette: "If the peasants don't have bread, let them eat cake."
House says, "She sends one of yours to the hospital, send one of hers to the morgue," which refers to the 1987 movie The Untouchables, a remake/update of the 1959 TV series of the same name. Actor Sean Connery plays Jim Malone, a veteran policeman, who helps Eliot Ness bring Al Capone to justice. The line references Malone's advice to Ness about responding to the Mob's escalation with more escalation.
Irv, the man who falls down for the commercial shoot in the opening scene, is played by Brad Grunberg. Brad is the brother of Greg Grunberg, the drummer for the musical act known as the Band from TV, which features Hugh Laurie on piano and vocals.