1950's Anaheim "Main Street" (the land wouldn't be called "Main Street", I just mean that it would be DCA's equivelant of Main Street).
As you enter the DCA, you pass through a small "orange grove" (don't ask me what happens to the Golden Gate Bridge or the mountain mural ) into a 1950's Californian small town street. It doesn't have to actually look exactly like Anaheim looked in 1955, but instead capture more of a general Southern Californian 1950's small town feel. There would be 50's cars, 50's music, a malt shop, all that kind of thing. (And yes, I remember "Blast to the Past" at DL). You could have a "newsboy" hawking a "local paper" with a story about that "ammusement park" Mr. Disney is building nearby. I don't want to get too far into immitating DL, but at the end of the street could be something fantasy-oriented and unexpected - as with the castle at the end of Main Street, except something distinctly Californian - that would somehow transition you into the other lands. (No idea what this would be.)
I know there's probably not as much room in the Sunshine Plaza as there is for Main Street in DL, but it doesn't have to be a long street, just a little town square or something.
I don't think they'll actually do this, it's just an idea I had .