Right, there has been rumors of a replacement for about the last 5 years, roughly around the time of the 10 year original lifespan. It seems likely that a replacement will happen, but when - who knows. The situation is somewhat like Star Tours. That replacement was rumored frequently for years, but took a heck of a long to happen. With the lack of any new attractions heading to Epcot other than the Test Track refurb, a new nightshow would be a way of giving Epcot something new, fairly quickly, and without physical building. They could very well go down that route in the next 12 - 15 months. Equally, I wouldn't be surprised to still see the current show running in 5 years from now.