I've only just found out that a a sequel to The Dark Crystal is in production. They will using real puppetry again with the use of CGI background. A lot of the original people are working on it and the Hensons are in charge.
official blog -
http://powerofthedarkcrystal.blogspot.com
http://www.imdb.com/title/tt0460907
http://en.wikipedia.org/wiki/Power_of_the_Dark_Crystal
from blog in sept '07:
The Jim Henson Company held a special Q&A session at the 2007 ComicCon International convention in San Diego. Brian Henson, Lisa Henson, John Chandler, Halle Stanford, Patrick Bristow and Julianne Buescher were on site to answer questions from the audience. Inevitably some questions about
Power of the Dark Crystal came up; here is what Henson had to say:
"We’re working on 'Power of the Dark Crystal' and those are animatronics puppets but with a whole lot of cool compositing techniques and animation enhancement that will be animatronics better then you’ve ever seen them done."
- Brian Henson
"All of this is cloaked in secrecy...there is something great coming along... Fans of 'The Dark Crystal' did detect that we were moving a little slowly, and it’s kind of true, we had a little setback but are back on track. The movie will not be coming out until 2009 so we’re not going to be showing anything for a while."
- Lisa Henson
no solid release date yet except for
2009 
If you've never seen the 1st one, watch it sometime and prepare to have fucked up nightmares...