One complaint about adding great new rides to DCA is "Where's the room?" And I agree. The park has been squeezed in and it results in little room for expansion and traffic problems on the Pier. At this point it seems the only way to add to DCA is remove something else. At that rate the park can never really get off the ground because it will have the same problems of not having enough attractions. So I offer a solution. The one thing we can remove in order to add a plethera of space.
Move the Grand Californian Hotel to their unused land which keeps starting the 3rd Gate rumor. I'm sure if you have been inside the Grand Californian or seen pictures, you realize this hotel takes up plenty of room with its many dining options, it's rooms, and the pool area and gym. This Hotel takes up about the same amount of space as the Hollywood Backlot portion of the park.
With that chunk of property open, DCA now has room to expand Condor Flats, Grizzly Peak (or whatever the forest section is), AND Paradise pier. Or you could add a new land. Maybe a historic area. Gold Rush era themed. Boom towns against the backdrop of the Grizzly Peak and an old San Fransisco waterfront against the background of Paradise Pier. Maybe a Chinatown area of the park, because of the fact Chineese immigration helped build California.
As regards to expansion, I have come up with ideas to expand from existing lands. A dueling coaster with a dogfight theme for Condor Flats.
An off-roading through california autopia ride where guests drive through the moutains of Calico, the Redwood Forest, the Crystal Caverns, the Snow Covered Sierra Nevadas, and a grand finale in Yosemite Valley complete with AA animals.
Under the Off-Road Adventure you would find a underground showroom hosting a pirates-type ride with Old West theming.
Paradise Pier can add Rockin' Rollercoaster or perhaps some sort of underwater adventure ride.
Even with these 4 new attractions, there should still be room to fit a nice restraunt for that corner of the park. This would allow you to turn some of the other larger restraunts in the park into attractions as well.
So we now have that Great Hotel sitting all far away. What do we do with that? We start a process of building other hotels on the same property. The moving of this hotel as with the building of others should be adequate time to assemble a monorail track from the sepperated property to the parks. When the hotels and monorail are finished, the current hotels can be taken down to make way for a third park. A water park in the theme of Neverland Island or Pirates or The Little Mermaid? Or a new attraction-based park with a villian theme or a Pixar theme (so they will stop cluttering up the other parks with miss-theming) or an Epcot West.
With the hotels down the street, Disney would have Downtown Disney acting as this central Hub to three amazing parks. And even without the whole relocation plan, just move The Grand Californian and a wealth of oppertunity is now possible at DCA.