there's actually a sequel that's going to be made
Here's an excerpt, which discusses the sequel as follows:
Current status: The planned sequel, The Power of the Dark Crystal, is still in development, though Henson emphasizes that it is not yet in pre-production. “At one point, it was written about as if it was moving straight into production, particularly when we had Genndy Tartakovsky (Dexter’s Laboratory) attached as the director.
SOURCE:
http://www.vulture.com/2014/05/henson-properties-status-report-dark-cr ystal-fraggle-rock.html?_r=true share