Neat ideas all around! I like
@spacemt354's suggestion to expand Sydney Disneyland's Pacific Wharf (1905 San Francisco) from DCA's Pacific Wharf out along the lagoon front, taking over Ariel, Goofy's Sky School, Jumpin' Jellyfish and the Golden Zephyr. Some of those attractions might retheme, some might vanish. And the Paradise Pier across the water (which remains unchanged) can take on more design elements from the Santa Cruz boardwalk, which is geographically close to San Francisco.
From memory, some of what Sydney's Pacific Wharf had:
* An original Tower of Terror which took inspiration from the Winchester Mystery House. We're keeping DCA's Tower themed to Hollywood, so we could consider some other sort of attraction for Winchester if there's interest
* The Alcatraz version of Tom Sawyer's Island. May not be needed, but still a fun theme.
* The cable car transportation attraction. It's redundant with DCA's Red Car Trolley.
* The Lombard Street wild mouse coaster, which can easily replace Goofy's Sky School.
* I'd proposed a Chinatown shooter dark ride attraction, about recapturing escaped monsters from Chinese myth. Was meant for Sydney's Phase 2. Never wrote it.
Contemporary Bay Area is very tonally unique from 1905 Pacific Wharf, and there's a lot of IP it can offer. Inside Out. Big Hero 6. TRON. Much of that has a sci-fi angle, something DCA is lacking (though a Marvel expansion would have that tone). Perhaps if we designated a Silicon Valley land for the modern sci-fi stuff, it wouldn't feel redundant with an old school SF.
A potential Marvel area could fit well alongside this sort of setting. I could see these two lands (Marvel, sci-fi San Fran) both fitting the western Simba Lot pad.
For Colonial Mexico, I'd say there's enough there to justify a land. I've proposed a historical water ride akin to POTC, something DCA needs anyway. There's also Zorro, who figures into the era when California switched from Mexico to U.S. statehood...could be good stunt show material. And geography and time period aside, I'm for a Coco attraction for this land too. The Dia de los Muertos afterlife is a rich topic, and I can see an interactive guitar dark ride being really special. Let's assume our 2012-era timetable leaves an empty spot in this land for Phase 2; once 2017 rolls around, Coco is a go! (For the Bug's Land space and the pad behind TOT.)
1940s Hollywood already claims the pre-GOTG Tower. To that we can add Roger Rabbit, Muppets (they can cross time periods with ease, like in Liberty Square), **** Tracy's Crimestoppers, and I might add The Rocketeer. He's late '30s Hollywood, and has amazing ride potential! For something non-IP, there's a common fan concept for a Hollywood version of Mystic Manor, something like an enchanted film projector which belongs to a faded starlet like Gloria Swanson in Sunset Blvd., a projector which brings old movie scenes to life.
The whole Backlot area (everything north of the Trolley street, including Monsters Inc.) could be thematically strengthened. Perhaps it could be a period studio backlot, or it could totally retool into something like the Hollywood Hills, where the rich and famous live. I like the Hills version (though it requires razing all the soundstage buildings that are there now) because it's more park-like and organic.
Buena Vista Street, Paradise Pier, Cars Land and the Grizzly Peak/Airfield areas are pretty solid already.
