On the official DisneyParks Twitter account (http://www.twitter.com/disneyparks), Disney has announced the following:
The Lights of Winter at Epcot has been enjoyed for years. But tech to operate the lights is obsolete, prompting us to retire the lights.
After several years, the lighted archways that would dance to music will be no more this holiday season.
The Lights of Winter was a series of archways with more than 30,000 lights that spanned the main walkway between Future World and World Showcase. The monorail also would pass through part of the display. The lights would dance to holiday music in coordination with the Fountain of Nations, creating a spectacular display.
As the Twitter post indicates, the current technology used to run the lights show is "obsolete," so instead of repairing or upgrading the system, Disney apparently is throwing in the towel.
So far, there's no word if Disney is working on something new to replace the Lights of Winter.