I think that having an attraction that can only be experienced by park hoppers is brilliant, and would be brilliant if WDW did it as well. I propose an omnimover connecting the African themed area of World Showcase with Africa in DAK.I can't really think of anything they could do now, the parks are just too far apart. It would great if they could do something similar to Uni.
Plus the fun of watching people freak out here about the greed of WDW forcing park hoppers on people would epic