No Export for You: Several (but not all) countries outside the US can't watch the videos on the site. Many fans aren't happy.
One of Us: Even before his and Jon's Star Trek trivia war at the Reality to Restore Sanity and/or Fear, Jon played a clip of Stephen reciting Aragorn's entire geneaology.
Asked James Franco, in a Tolkien fan Nerd-Off, why Galadriel came to Middle-Earth. And Colbert corrected Franco with stats straight out of The Silmarillion.Badass in the annals of nerddom.
Real Life Relative: Stephen's children occasionally show up. One of Stephen's brothers, a lawyer, has appeared at least twice, the last time at the start of the Vancouver Olympics series to tell him he can't legally use the word "Olympics". Or "Vancouver".
Written in Infirmity: When Stephen broke his wrist, he milked it for humorous effect by pretending to become addicted to his painkillers and delirious from overdosing, and made sure to call attention to this "Wristrong" (Wrist Strong) bracelet at every opportunity.