The dedication to John "Yomi" Rothlisberger (1919 - 1993) in the end credits of the episode refers to a resident of the town Roslyn (where the series was filmed) who appeared as an extra in pretty much every episode of the show and with whom the cast and crew of the show had become very friendly over the years.
Mike's getting on the bus "I'll be there" speach is a parody of Tom Joad's speech at the end of "The Grapes of Wrath" just before he leaves his family.