Dyeing for Your Art: Actually averted by Anna Hutchinson, who is a natural blonde, playing a character who has just dyed her hair blonde.
Director Displacement: Poor, poor Drew Goddard. No recognition for writing Cloverfield due to it being produced by J.J. Abrams, then no recognition for co-writing and directing this due to Whedon being a co-writer...it was his first directing gig too!
Direct-to-Video: It was originally slated for this in Australia and New Zealand. Fans complained. It subsequently got a limited theatrical run in June of 2012.
Fake American: Curt is played by Australian actor Chris Hemsworth, while Jules is New Zealand actress Anna Hutchinson.
Fan Nickname: The Sugarplum Fairy monster is often referred to by fans as "Ballerina Dentata."
Re Watch Bonus: The talisman Sitterson kisses on the first death has the same pattern as the floor in the room with the five sculptures at the end.
Similarly, rewatch the scene with the talismans in the basement and try to figure out which one belongs to which monster in the containment rooms.
Star-Making Role: Chris Hemsworth. According to Joss Whedon and Drew Goddard the dailies from the scene where Curt reveals Jules has been killed were so well-received by the studios that it actually locked him in for lead in the remake of Red Dawn (2012) and got him a callback for Thor which he would come to star in.
Steven Ulysses Perhero: The greensperson (crew member in charge of acquiring plants and trees for a film set) on the film is named "Glenn Foerster". Drew Goddard and Joss Whedon mention on the commentary how thrilled they were at his name.
In both this film and Paul, Sigourney Weaver plays the head of an evil organization hiding an otherworldly secret from humanity; she appears only by voice until the very end of the movie, when she presents herself and tries to kill the protagonists, only to be killed herself. (then again, both serve as a Casting Gag, inverting her most famous role of someone who gets screwed by a Mega Corp.'s questionable decisions)
The various Left 4 Dead characters are present because there was supposed to be special L4D downloadable content based on the film. The deal fell through, but the characters didn't seem out of place, so it was easier to keep them in.
The studio wanted the office celebration scene cut down. Drew Goddard was so upset by this and couldn't bring himself to do it, that Joss Whedon phoned the studio to inform them they would not.
A tie-in book reveals concept art for other monsters that weren't used. They include an Expy of Creature from the Black Lagoon, a monster made of seaweed, a Threatening Shark, a zombie Native American hunter, a pirate and several alien monsters. Another book mentions creatures representing real-world fears - such as a vagina-toothed woman, a dog-headed alligator, a Minotaur, a giant rabbit, a three-headed baby, a group of lava people and the freakiest of all - a woman with snakes for pubic hair.
Word of God: 'Kevin' listed on the board is described by Drew Goddard as a seemingly nice guy "who looks like he might work at Best Buy" - who then dismembers people.