The idea behind EPCOT was you would choose to living in a living laboratory where they would provide prototype, experimental equipment (Wouldn't be much of an EPCOT if they chose standard GE products). And thats the problem. John Hench once did a scenario "Hi, we're here to replace your kitchen of tomorrow with a newer one." "But I haven't even figured out most of the current one" "Well, it's experimental". You can build a high-tech city of Today, but not one with experimental, prototypical equipment that may or may not work. Hence the switch. The Future World Theme Center was supposed to showcase upcoming ideas before it merged into EPCOT Center. Let's think of even the foward-thinking things that were done and tried though and the success rate: Monorails (too expensive, failed overall), WEDway (underpowered, unable to change elevation, failed), modular room construction (failed, too expensive. Cheaper to modular the whole building), AVAC (failed, too many issue), methane-powered engines (failed), laser-disc based info systems (already outdated).. and so on. Because they were done on a limited level, they didn't really impact guests just the systems.