Important: Understand that this page contains (mostly) user-submitted, non-verified content. Hence it barely contains all references that exist, but only a mere fraction. If you've spotted a reference, feel free to add it down below with a compatible description. Add links if needed.
There's an NPC by the name of Lun-Chiωτϖ located in Kun-Lai Summit, near the Temple of the White Tiger. Under her name appears the title, <The Streetfighter>. This would appear to be a reference to the character Chun-Li, from the Street Fighter game series.
A quest called Unsafe Passageωτϖ given by Koro Mistweaverωτϖ in Krasarang Wilds results in a part of dialog from the game Skyrim, where the guards would repeatedly say "I used to be an adventurer like you, then I took an arrow in the knee", which also became an internet meme later on. In the quest, while escorting Koro Mistweaver, you are attacked by a group of Riverblades, after which Koro would say: "Help me up, <name>. I... I took an arrow in the knee...".
An NPC located in The Jade Forest by the name of Dook Ookemωτϖ is an obvious reference to the main character of the video game series, Duke Nukem. His quotes are also said to be based on the character.
There's a house on top of a mountain in The Jade Forest, which has a reasonable amount of balloons connected to it. Inside the house, is a pandaren named Karωτϖ(which would be a reference to the old man in the movie, named Carl). Outside the house is a single grummle by the name of Rusty Nailωτϖ , carrying a backpack, accompanied by a fox named Digωτϖ - these would be referring to the young boy by the name of Russell, and the dog, named Dug.
The achievement Number Five Is Aliveωτϖ is a reference to Number 5, a designation given to 1 of 6 robots in the movie "Short Circuit". After being struck by lightning, "Number Five" becomes convinced that he is alive, and not just a machine. The achievement itself is the declaration made by the robot: "Number 5, not a machine. Number 5..... Is alive!"
There's an NPC named Adeleωτϖ located in Townlong Steppes, more specifically in an area named The Widening Deep. The NPC moves by rolling on the ground, and with the name of the location, this is an obvious reference to the singer Adele and her song "Rolling in the Deep".
There's an area named Honeydew Village located in The Jade Forest. This could be referring to Simon (better known as Honeydew), a member of the YouTube Let's Play group, Yogscast. Yogscast is an internet sensation that has promoted World of Warcraft in many ways, and therefore it would only make sense for this to be a dedication to Simon and the entire Yogscast team.
There is a Isle in the Krasarang wilds on which a bunker is with 7 skeletons around and a Stack of Papersωτϖ which is a reference to the Log printout from Lost (but the note on the papers is a reference to Diablo 3 as stated above).
The achievement What Does This Button Do?ωτϖ is a likely reference to Dexter's sister Dee Dee who would often say, "oooooooooooo, what does this button do?" before pressing buttons at random on various machines in his lab.
The Singing Pools, an area which is located in the pandaren starting area, The Wandering Isle, could be a vague reference to the Japanese manga series, Ranma ½, as if you fall into any of the pools, you're transformed into an animal.
On the Wandering Isle, just up the stairs from Mandoli Village is an NPC named Zach Chowωτϖ and his pet tiger Azunyanωτϖ. The tiger's name could be a reference to the K-On character Azusa Nakano, who has the nickname of Azunyan.
There's an NPC by the name of Lon'li Gujuωτϖ in Kun-Lai Summit. This NPC is referring to the last Pinta Island tortoise, who became world-famous but passed away on June 24, 2012. If a player emotes something such as /wave or /love at the tortoise, he'd start to follow the player for a while.
Cornan <The Barley Barbarian>ωτϖ, an NPC in Valley of the Four Winds appears to be a reference of Conan the Barbarian, a fictional sword and sorcery hero that has been included in many different sorts of media (games, movies, comic books etc.)