Pixar/WMG

John Lasseter is the reincarnation of Walt Disney.
There's just no other explanation for Pixar's uncanny success. John Lasseter IS Walt Disney.
 * Makes sense in a symbolic way at least.
 * But wasn't he born before Walt Disney died?

Joss Whedon is the other reason Pixar is so epic, after John Lasseter.
He worked on the script for their first film, Toy Story, and obviously it was a huge success. Every other film they have made has been, to some degree, a success. So many components of their films mirror what Joss has been doing with his shows and films: telling a simple story that often involves a created family, with what seems like a ridiculous premise, yet manages to be emotionally resonant to millions of people. Joss isn't working for Pixar anymore, but he's there in spirit.
 * That would explain all the soul crushing.
 * It also explains Cars 2- In order to make The Avengers, he had to give it his all- which meant taking the part of him at Pixar away. With Joss gone, Brad Bird making Mission Impossible 4, Andrew Stanton making John Carter, and John Lasseter running Pixar and Disney at the same time, they couldn't bring themselves to their usual standards.

All the movies take place in the same universe
With the exception of Cars, The Incredbiles, and Brave, which just can't be tied in, all of the movies take place in one universe. This is the reason characters continue appearing in each other's movies.
 * Jessie becomes Boo's toy aftter Andy gives her up--this is why we see her in Boo's room.
 * It's another Jessie doll. Sid tries to steal it in one of the Monsters Inc. comics to prevent what happened to him from happening to anyone else.
 * In Jessie's memories of her owner in Toy Story, they play by a tree that looks suspiciously like the one in A Bugs Life.
 * Except that one was on an island in the middle of a riverbed and the other is in top of a hill.
 * Landscapes change over time. Maybe a flood washed away part of the Toy Story hill, and the river changed its course before A Bugs Life.
 * Monstropolis is in a dimension tied to the other Pixar characters', or in a place hidden very well. This is why  is also in A Bugs Life.
 * Buy n' Large is clearly a big manufacturer during the events of Toy Story 3.
 * You could even fit Cars in there. Timeline: Starts with Ratatouile, Bug's Life, Finding Nemo and Toy Story all in modern day, just in four different areas. The Axiom leaves Earth in the near future. In the 600 years that it's in space, humanity dies out and sentient cars become dominant. How can cars with no limbs or hands build anything? Simple; they didn't, the robots that were on Earth did. Sometime during those 600 years, the cars all die out (I imagine reproduction is slow, if existent at all). After that, the rest of the events of Wall-E take place. The reason there are still trees and plants in the Cars time is because the Cars, after becoming sentient, did some cleaning and replanting of some areas with the help of robots, but once they died off, things went bad again.
 * Or, perhaps, the cars are the distant, possibly even techno-organic offshoots of the Axiom robots who helped restore Earth. The humans went back to space, presumably to colonize/explore the universe, and the "children" or Wall-E and Eve essentially inherent the planet.
 * Boo is Bonnie. Its Kind of plausible.
 * Well, Bonnie would clearly be the older version if so. And they moved at some point, probably because the poor girl wouldn't quit talking about her recurring hallucinations of a giant, blue Kitty. She took a liking to  immediately because it reminded her of the Jessie doll she used to have, and then , she likes it for the same reason. Personally, though, I can't imagine Monsters Inc. taking place in the same universe as Toy Story. While the toys actively and effectively hide their secret lives from humans, monsters only hide theirs from adults, if anyone. Plus, kids in Monsters Inc. are said to be getting harder and harder to scare, which most likely means the children of previous generations still remember that monsters are real and humanity is accustomed to their presence. It at least explains why the kid at the end   So, in a world where humans are aware that monsters sneak into their children's rooms at night, and don't care, what reason is there to hide the existence of Living Toys? Makes me wonder if the upcoming Monster's Inc. 2 will approach this issue of human-to-monster relations.
 * Regarding your mention of "children getting harder to scare", that was explicitly shown to be the result of scary movies being easily available to kids and numbing their sense of fear. Also, the kid at the end is employing the Rule of Funny. The entire movie of Monsters Inc is a play on if the monsters in closets that kids are scared of were real, but it never says that this isn't our universe. It's just one with a single surreal element added.
 * Two words: Pizza Planet.
 * One more: Dinoco.
 * Another way that Cars can be made to fit into the proposed Pixarverse comes from a throwaway line in Toy Story 2, when Hamm mentions speaking to the lawnmower next door. This suggests, if not outright declares, that appliances are sentient as well as toys, and maybe that includes cars. After humanity dies out or moves on, the cars stop pretending to be inanimate, and they inherit the Earth. Appliances being sentient could also place The Brave Little Toaster in the same universe, but I'm not even going to start on that x)
 * Lawn gnome. He spoke to the lawn gnome next door.
 * Oh my, I'm most dreadfully embarrassed. Are you sure?
 * Either way, it still sounds like a pretty nice bet. :)
 * alternativly, Cars might just be in a paralell universe like Monsteropolis.
 * It's too early to make a solid theory yet, but to start the brainstorming for Brave's placement is that it takes place in the the Dark Ages when magic was more abundant with spirits and magical creatures existing alongside humans. But to a due an event, possibly Merida's major blunder that is hinted at, The Magic Goes Away to an extent. The magical creatures leave Earth and settle in another dimension, which would eventually be called Monstropolis (They in turn lose their ties to magic as well), while magic has lost much of its power and presence on Earth, only manifesting itself in animating toys, giving sentience to animals, and granting certain people superhuman abilities.
 * the world of Cars is on another planet and the cars were created by Syndrome from The Incredibles. He travelled to another planet at some point to experiment with ideas to give everyone special powers and created sentient cars that would let humans not have to drive themselves around anymore, but something went wrong and he abandoned the cars.

Alternately, all the movies take place in the same universe...
But it's an Toon Town - like universe, where everyone is an Animated Actor. It explains why Woody's doing the clapper in the Bug's Life outtakes and why Flik and Heimlich show up in the Toy Story 2 outtakes- they like to help out on each other's projects. Likewise, when characters show up in other movies, they're actually cameos by the actors. The reasons settings look familiar from one film to the next (like the Ant Island tree showing up in Toy Story 2) is because they reuse the sets to save on their budgets. (Well, it's certainly a more cheerful theory than the above...)

I actually agree with both of these theories. Brings a nice unity to the Pixar universe.

Lasseter, Stanton, Doctor and the other Pixar head honchos are Dementors
Friendly ones however - they're perfectly content to feed on their audiences' feelings instead of their souls. Their movies are so full of heartstring-tugging and weepiness because they need those emotions to stay alive. As time has gone on, they have perfected their techniques at stirring such emotions, hence how they got everyone on the planet to cry by the first ten minutes of Up and throughout the entirety of Toy Story 3.


 * Weird, I was thinking that same thing last night. If they are, then something tells me Brave will have something INCREDIBLY weepy and heartbreaking in it too, to keep the masquerade going for the outsiders. The tours? Showing some their true identity and hoping the secret doesn't go out to the world. Government agencies/villains/the paparazzi would hunt them down and use them for evil purposes if the secret was blown--hence the exclusiveness.

Brave will be rated PG
Why? Because all other Pixar movies about humans have been rated PG.
 * Except Ratatouille. Really, it was about Linguini, Remy and company were just the Spotlight-Stealing Squad.
 * Confirmed!

Pixar deliberately made Cars 2 weaker than their typical films
It makes perfect sense—in order to make their next big feature "Brave" stand out all that much more, as well as to mess around with their audiences, Pixar took it easy with Cars 2, making it a potboiler feature made to keep milking the Cars gravy train, since they knew the brand name and merchandise alone would guarantee it to be a financial success and make oodles of cash for them, regardless of critital thrashing. And then they pour their all into Brave, which would quickly Win Back The Crowd, and people will just look back at Cars 2 as just a little bump in the road.
 * oh, and this is to make Pooh look better too.
 * It also makes sense retroactively. After Toy Story 3, which became the biggest CGI film ever financially and critically, there was no way for Pixar to go but to go down. So they went as down as people would've thought possible. It's really only with their special reputation (and ticket sales) that Pixar would have the guts to attempt a Plan like this.
 * Only problem with this theory: if they DID try to make it their worst it would be their best.
 * Hey, if it worked for Weird Al Yankovic (He deliberately made his song Girls Just Want To Have Lunch awful and many fans feel similarly) it can work for them.


 * Pixar: Sweet Manipulatively Clever Chess Bastards since 1995. We wouldn't have it any other way.

Cars is a fictional Movie in the pixar universe
Why not?
 * Which has fictional Pixar movies within its universe? "Yo dawg, I herd you like Pixar..."

Brave's tagline is retroactive and ironic
Change your fate, eh? This could be the tag for three reasons. In-movie: It's about defying tradition. From a whole Pixar series perspective: after the debaticle that was Cars 2, it's up to Brave to change their fate and show that their Dork Age is not this day. Meta perspective: this is their 13th film. Therefore, they're trying to make it their best film to fight the unlucky 13 rule.
 * Seeing as how some are predicting that Dreamworks Animation will rise and lead to the fall of Pixar, it could also be seen as trying to defy that prediction.

The Pixar Film That Takes You Inside The Mind will be an homage to other Journey to The Center of The Mind films
Much like how The Incredibles was an homage to superhero and James Bond movies, and A Bugs Life was an homage to The Magnificent Seven and The Seven Samurai, TPFTTYITM will be an homage to films like Inception and Paprika, filled with lots of Deranged Animation, andMindScrews.
 * Oh, and don't forget Dark City.

Geri of Geri's Game plays against his split personality.
It's why he feels as though he's in deep competition, despite it being against himself.