Tom (Cruise) and Brad (Pitt) are mentioned as Vampire Council members who didn't have availability. They played Lestat and Louis in Interview with a Vampire.
Viago introduces himself as Viago Von Dorna Schmarten Scheden Heimburg.
According to Jemaine Clement, Paul Reubens brought his wig from Buffy the Vampire Slayer (1992) for his cameo, which he had modeled on his infamous mugshot - because, Reubens said "it was the coolest I've ever looked".
First time the film crew is ever shown that is documenting the vampires.
The Floating Woman is played by Kristen Schaal who was Mel on Flight of the Conchords.