A press release about entertainment at Walt Disney World was just released. Part of it shows that during the slower times of year, Fantasmic will only be performed 2 nights a week:
We regularly evaluate and refine our operations. At the same time we unveil The American Idol Experience in January 2009, we will make an adjustment to our operation by offering Fantasmic! on select evenings each week. Fantasmic! will be performed two times weekly –generally Mondays and Thursdays – and more often during our busiest times of the year.
On nights when Fantasmic! is not performed, Guests (with appropriate ticket media) will continue to have the opportunity to enjoy nightly fireworks spectaculars such as Wishes at the Magic Kingdom® Park and IllumiNations: Reflections of Earth at Epcot®.
Showtimes will be published for Guests in the Times Guide, which is available at the theme parks, and online at disneyworld.com.