Wow, great stuff there!
That's the plot of land for a future hotel. The Carousel Inn, the hotel property Disney just bought, can be seen in the middle bottom of that photo. It's the circular black turret right on the bottom of the photo. That slim piece of property connects directly with the surface level parking lots and office park that Disney now owns on the backside of that property.
The Carousel Inn would be razed and become 50+ foot wide skybridge over Harbor Blvd., landing on Disney property on the other side of Harbor. The new hotel complex would take up all of the land currently used for shuttles, Toy Story buses, and some "Backstage" uses behind Tomorrowland. At least that's what I learned at an OC cocktail party with some well connected folks on their third martini.
That photo also makes it easy to see how they could connect the new hotel to Disneyland via Main Street behind the Opera House, or to Tomorrowland around Space Mountain. Or both.
All future buses, shuttles and cars would unload or park in the massive structure facility, then everyone would go over the skybridge to get to Disney property. It's easy to imagine a series of moving sidewalks speeding up the process through the skybridge and parking structure, like big airports or the Universal Orlando parking facility.