LeVar Burton makes the fifth person from Star Trek franchise to be on the show. The others are George Takei, Wil Wheaton, Brian George, and Mark Harelik.
The line "The horror" was referencing the film Apocalypse Now (1979). The line was also used in a similar fashion in The Dead Hooker Juxtaposition (2009).
Amy mentions that if Leonard was the center of movie making they'd all be singing "Hurray for Leonardwood." There is, in fact a Fort Leonard Wood in southern Missouri.