Bart tells Marge that Homer told him that he was one Uday who didn't need a Qusay. This is referring to Saddam Hussein's two brutal sons.
Brothers Bart sees in his dream of "Bro-Town U.S.A.": the Marx Brothers (Groucho with cigar, Chico playing piano, Harpo playing harp); the Blues Brothers ("Joliet" Jake [John Belushi] and Elwood [Dan Aykroyd]); the Mario Brothers; the Smith Brothers (brand name of cough drops); Sideshow Bob and his brother Cecil; the Wright Brothers; Eli, Peyton, and Cooper Manning; and the Smothers Brothers (Tom Smothers and Dick Smothers, whose comedy-variety TV show was canceled by CBS in 1969).
When Bart, Milhouse, Nelson and Ralph are at the bus stop there is clear parallel with South Park. Bart, Milhouse, Nelson and Ralph are each dressed as Stan, Kyle, Cartman and Kenny, respectively. Also, Otto comes into screen driving the school bus where he hits Ralph, to which the boys say "You killed Kenny!", a clear reference to the same line in South Park after Kenny is killed (which used to occur every episode).
Peyton and Eli picking on their brother Cooper is based on the 3rd Manning brother's broken athletic dreams. Cooper was a star QB in high school just like his siblings and would have played college football (and probably reached the NFL), but he suffered an injury where he could no longer play football because he would have been risking death or complete disability if he was hit violently again. He's now a successful businessman in New Orleans.
This is one of the two animated projects to feature Huell Howser. His next and last one was Winnie the Pooh (2011) released 2 years later.