Future episodes become inundated with references to the Olympics.
Related to the above, Michael Phelps appears in a future episode.And the song done by David Armand for "Face the Music" is "Harder, Better, Faster, Stronger".
Other guests that may come back thanks to Whose Line involvement:Richard Simmons, Stephen Colbert, Whoopi Goldberg, Kathy Griffin. Sid Caesar could probably end up doing a two-parter thanks to the sheer number of tales he has, including that time he punched a horse. Really.