The people in the Couch Gag are Seymour and Agnes Skinner Jimbo, Kearney, Lenny, Moe, Comic book Guy, Hans Moleman, Ralph Wiggum, Ned, Rod and Maude Flanders, Milhouse, Groundskeeper Willie, Krusty the Clown, Sideshow Mel, Apu, Mr. Burns and Waylon Smithers.
The song the KBBL guys use for a news flash is Duffman's "Oh Yeah" theme song
When Homer daydreams about his funeral in The Graveyard of the Future, a tombstone with the name Tamzarian on it can be seen. Armin Tamzarian is Principal Skinner's "real" name from "The Principal and the Pauper" (even though a court order was stated that Principal Skinner's real last name could never be mentioned again under penalty of torture and it was non-canon).
The Simpsons show Homer a film reel including footage of him in space (presumably in "Deep Space Homer", although the footage is new) and in a boxing match (in "The Homer They Fall").
The last appearance of an unfamed additional voice actor before his death in April of 1998: Matt Gerald.
He voiced the boy's dad.
The episode title is an allusion to Thomas Edison's nickname, "the Wizard of Menlo Park".
The Robot at Homers Funeral Is a reference to Robbie the Robot.
The promo image for this episode was also used in the Jeopardy! category, "Readings from Homer".
The two black birds (actually crows) at Homer's imagined funeral are Heckle and Jeckle. Heckle and Jeckle are Magpies.
Other cultural references are:
White Heat: when running on a globe, Bart exclaims "Top of the world, Ma!", a reference to the second to last line of White Heat, "Made it, Ma! Top of the world!";