DCA is my favorite Disney Park on either coast. World Of Color is such a great way to finish a day there.
The new amphitheater being built at AK is to house a show using some of the World Of Color technology.
We only got to spend a few hours in there but we were more impressed with it then DL (early returns though).
The similarities between DL and MK hurt the "wow" factor of the second one you visit. I enjoy noticing the little differences, but that's a quirk of my personality. There's a lot of elements of DL (and DCA) that work because of the reliable Southern California weather, pieces DL keeps open air and MK (and other WDW parks) enclose because of the storms that frequently pass through central Florida. For example, the Winnie The Pooh ride at DL loads/unloads outside in Pooh Corner. MK won't risk temporary closings of kids' rides because of rain.
DCA needed a roller coaster, so they built California Screamin', an old school open-air wooden coaster in the spirit of Southern California pier amusements. Contrast that to DHS putting the entire Aerosmith queue, ride, and merch inside a building.