The two microcephalics appear (Zip and Pip) and they chant the "one of us" line several times.
Randal and Dante reference Caddyshack, while playing golf
Randall references Dante's relationship as "Dante and Caitlin 2: Electric Boogaloo"
A comedy writer consults a book called "How to Write Cartoons by Seth MacFarlane" (Seth being Family Guy's creator/writer/star) and then suggests a Family Guy-style pop-culture cut-away gag.
The episode keeps refering to the Matrix
The name of Darth Maul appears on the costume ball poster
The last part of the episode is a spoof of this Daffy Duck cartoon.