How about putting all the lands around the a large lake so it is like Epcot's World Showcase. You walk down the Main Street Studio street suggested, then there is a land themed to every single Pixar film likes the countries in World Showcase.
There's are my ideas for lands (sorry that none of these ideas are extremely original):
Sydney Harbour- a recreation of Sydney harbour complete with the bridge and opera house with attractions based on Nemo. Inside the Sydney Opera House is Finding Nemo- The Musical. There is a cruise ship docked in the harbour and inside is Turtle Talk with Crush (set up in the same style as Turtle Talk in DisneySea).
Sunnyside Boardwalk- A seaside Boardwalk (like Paradise Pier) hosted by the Toy Story. Attractions here include Toy Story Mania, Rex's Dino Land Arcade and Bo Peep's Carousel.
Luxo Space Port- A futuristic Pixar style Tomorrowland themed against a port for space ships (and named after the Pixar mascot). It is also the base of Star Command. Here you'll find an upgraded Buzz Lightyear Astro Blasters and Star Command Space Mission (a Pixar-fied much better version of Mission: Space). And in the Space Port, the Axiom Ship from Wall-E has landed. Inside it is the Wall-E Axiom Coaster- a half dark ride/half spinning coaster based on the film. Guests sit in chairs based on the
seats in the film, in the first part of the ride they travel around the ship with Wall-E and Eve loosely following the story where they meet the captain Auto and in the second half they are thrown down the chute and out into space where the guests spin widely out of control.
A Bug's Land- Same as DCA, only much better theming
Radiator Springs- Same as DCA, only larger with more shops and restaurants such as Flo's Gas, Cozy Cone Motel and a Sci-Fi Dine In style restaurant
Monstropolis- Based off the city in Monsters Inc. The heart of the land is dominated by the Monsters Inc building. Inside is Ride & Go Seek from Tokyo and Monsters Inc Door Chase, a duelling inverted coaster where guests ride the doors in the film and compete to see who can scream the loudest and create the most power. Also is Mike Wazowski's Monsters Unleashed!, a variety show hosted by everyone's favourite monster, similar to Turtle Talk. In it Mike interacts with the audience, tells jokes and does musical numbers such as 'Put That Thing Back Where It Came From'. There is also Harry Hausens restaurant, the Sushi restaurant from the film.
Nomanisan Island- A large island featured in the movie the Incredibles. There is a large volcano in the centre. The main attraction is The Incredibles Adventure, a ride similar to the Spiderman ride at Universal, in which the Incredibles must battle all of their nemesis who have joined forces. Another attraction is The Incredibles 4D, based on the movie which includes effects such as water spray when Dash runs on the water and the whole theatre moving when the Omindroid is rolling across the floor. Other attractions include Island Transportation Pods, based off the transport in the movie, and the Edna Mode show: another interactive character show. In it guests are seated in a large theatre for the recording of Mode, Edna's daytime talk show. There are various segments to the show including the style segment in which she criticizes audience members dress sense; celebrity interviews in which pre recorded interviews with Edna from real celebrities are played; and a Jerry Springer parody in which a Pixar couple come onto the stage to discuss their marriage and it is revealed that the wife has been having an affair with a randomly selected audience member. I've written a whole script for this show if you're interested.
Paradise Falls- Based on the tropical rainforest in Up. In it Paradise Falls River Expedition, a Splash Mountain style log flume ride based on the film. Guests travel in a log meeting all the characters before plummeting down Paradise Falls at the climax. Also here is Flying With Russell and Carl: a balloon ride where guests sit in Carl's house.
Place de Paris- The setting for the Ratatouille film with cobblestone streets and a huge fountain in the middle. The main attraction is Remy's Adventure, an omnimover dark ride in which guests are shrunk to the size of a rat and dart around the kitchens and the streets of Paris. Also here is Cookalong Live With Remy and Linguini, a live cooking show with the two characters where things go disasterously wrong. And of course you have to have Gusteau's Restaurant.
They are my rough ideas for a Pixar park.