So far only three of the main characters have alluded to a fairy tales. Ruby being Little Red Riding Hood, Weiss Schnee being Snow White and Blake Belladonna being Belle. Yang appears to be associated with a multitude of fairy tales including Goldilocks, Cinderella, Sleeping Beauty and The Golden Bird. However, Monty Oum has stated that the basis for Yang was in fact Goldilocks.
The first letter of each of the four main characters name refer to the title of the series, they can also be associated with the color. Ruby, Weiss, Blake, and Yang.
Out of all four trailers "Red" does not have an opening sentence (but it could be the tombstone message). So far each could be taken literally relating to the characters backstory in the series:
White - has had to deal with a great loss, and even though she may (not) feel sorrow, what was lost is irreplaceable.
Black - is taking on someone else's ideals and becoming smothered by them. She is looking for a way to liberate herself from the burden.
Yellow - was judged for not being similar to the rest, but for every misstep that occurred she became internally different.
In the "Red" trailer, the tombstone reads "Summer Rose/Thus Kindly I Scatter", an allusion to Thomas Moore's poem, The Last Rose of Summer.
Because of how Red vs. Blue ended and because the first RWBY trailer was placed right after the credits, many fans assumed RvB had finished. However, this is not the case. In Podcast 191, Monty Oum, Gus Sorola, and Miles Luna all stated that they will be continuing to make Red vs. Blue as long as people are willing to watch it.
People believed that the 'B' stood for Blue, in accordance with the more commonly know 'RYB' which defines the primary colors usage. This was later proven untrue when the trailer cemented it was in fact Black.
Weiss' sword, Myrtenaster, appears to translate, from German, as 'myrtle aspen', both of these being varieties of plant.
Weiss' name is German for "White", which may be an example of what Monty suggested about the naming customs of the world in RWBY.
RWBY is the first main Rooster Teeth series to be 100% animated.
The Black trailer is the first trailer to have fully voice-acted lines, and is also the first trailer to reveal a supporting character.
The Yellow Trailer features remixes from the other three pieces of music, as well as Yellow's appearing during her final battle.
The DJ in the Yellow Trailer parodies the artist's headgear of DJ Deadmau5, with it being a black bear head instead of a red mouse head.
Miltia and Melanie could be parodies of Delia and Deidre Dennis from the Batman Beyond Universe, where the characters have the same interactions with each ending the sentences with the sister's name.
The original voice actor for Junior was supposed to be Gavin, however Monty Oum decided that he sounded "too important" and used Jack instead, saving Gavin for a later role.