I would either make it an add on of the SPACE Pavillion, with different rides than JDM OR....make a pavilion on the ecosystem and environmental changes in nature (NOT the same as the land)
Probably what I might as well do; taking Body Wars out of the picture for a while and placing in Incredible Journey Within, perhaps this could work. However, as Epcot is supposed to focus on the innovative future, this could mean focusing on medical innovations that could change (in case you forgot). Perhaps a looks back to health history and into the future might help?
You could take a leaf out of Frontiers of Medicine, for example, but that's another story.
Keep it empty so it can be the focal point of the new annual Tech Fest. Perhaps staging area for TED every year and televising on one of Disney's outlets.