If they already have 50 pages of the muppet script it means they are into the project. I think he will be finding time to hammer the rest out in his spare time.
I keep hearing Segal & Stoller are taking on different projects as they are hot right now. I suppose we should all have patience... I mean we've waited this long.
It takes quite a while to make a film. Well, if you want to do it good. if you rush through it (like the Oz film clearly was), you'll wind up with a piece of dirt. When was this announced? A month or so ago, and they're already on page 50 of a script? That's not too long a time since the project was first announced. the worry should happen at the end of the script writing stage. But until then, we're just getting the beginning of a first draft of a script. We should be in script stage for quite a few months yet. And once again, only the first draft. look how long the Fraggle Rock film is taking to develope.
And once the script has been finished, expect a long period of time where nothing happens. that's preproduction.
That said, they even used the drunken Muppet Show clip for a new TV Trailer.