Marge mentions that Lisa could be the first Simpson to graduate from college, though Marge is revealed to have graduated from Springfield University in That '90s Show (2008). This is still technically true, as Marge graduated from college as a Bouvier.
The proprietor of the Magic Shop first appears by stepping through a poster proclaiming him to be "The Amazing Herzog". He's voiced by Werner Herzog.
WILHELM SCREAM: Heard when Lisa's presidential predecessor concedes.
Spider-Pig appears in the opening credits.
Couch Gag: Homer and Marge appear as birds in a nest. When Homer jumps in the nest, he cracks the eggs in the nest and then samples them and says, "mmmmm!"