What Could Have Been: The Honorverse was originally going to be timeskipped several decades, following the death of its namesake character. Her children would have continued the action. The Eric Flint collaboration Crown of Slaves nixed this original plan; its espionage plot ended up fast-forwarding the conflict by putting pressure on the Mesans to enact their plan early. As a happy side effect, Honor was spared, cutting off what would probably have been the greatest fan rebellion in modern Sci-Fi literature.
Write Who You Know: In A Beautiful Friendship, the Harringtons have a meeting at a restaurant called "The Red Letter", owned by a person by the name of Eric Flint. The fictional Flint is said to hail from the world of New Chicago, described as "a dumping ground for radical anarchists, socialists, and - especially - every member of the Levelers’ Association the government could round up after Old Earth’s Final War". The Real Life Flint, an occasional co-author with Weber in this and the 1632 series, is a self-admitted socialist, and currently lives near Chicago. Also qualifies as a Shout-Out.