A couple of points:
WDW has four theme parks. I like the idea that they are different, with different themes.
Some have suggested that Disney is trying to turn all of their parks into Magic Kingdoms. I hope that doesn't happen, and that each retains its own identity.
I understand that today's audience is looking for more "excitement" and new elements. But the most visited park is Magic Kingdom, and their most popular attractions continue to grab the audience's attention with very few changes over the years. But the MK has evolved as a park over the years, and most attractions weren't reliant on video technology (which can age rapidly). Think about the portable phone Ellen displays in the Energy pavilion for example.
Disney can add IP to Epcot (IMHO), as long as it furthers the story of creativity, innovation, etc. to address our energy problems, protect the environment, advance technology for a better, healthier world. Epcot has always been my favorite park. But when story lines become outdated (Energy), or the technology used to tell those stories isn't updated (imagine Body Wars with the kind of update Star Tours received), and when "World Showcase" only showcases the same 11 countries it did in the late-80s, it is easy to understand why people find the park tired and less desirable. Whatever changes/additions need to be worthy of the original aspirations of the park.