Helloooo everybodyy!
I was SO PSYCHED to hear this news, and I come here (I'm not REALLY supposed to forum-post at work) and so many people are already so worried about it. Be happy! The cup is half-full not half-empty!
I know that you look at Jason Segel and see that he's one of the Apatow gang and get nervous, but does anyone here watch How I Met Your Mother? Jason plays Marshall, who is pretty much the sweetest character on tv today, and if you listen to the commentary you can see that Jason is just the same.
Obviously "Sarah Marshall" humor is NOT Muppet humor, but it IS good enough for Apatow and studio execs and it predicted to be a big hit. So after this movie hits Jason will have a solid writing credit to his name--something that can only help the new Muppet movie if his name is attached.
Another thing that makes me excited about it is that he approached Disney about it. They didn't court him. That's got to mean that (a) he's a Muppet fan, (b) he wants them to make a big comeback and (c) he believes in himself. I think it's an absolutely brilliant choice. He's old enough to remember/have experienced the Muppets at their classic best, but he's young enough that he knows what works today and, no offense to the wonderful people in the Muppet family, recently they haven't seemed to make the Muppets work for the new generation (coughMWoOcough). I think it could work wonderfully and---and this can only be a good thing--it puts attention back on the Muppets again! When "Sarah Marshall" is a big hit--and it will be--it'll be said that Jason Segel is currently working on __________, _________ and writing a new movie for the Muppets.
So please, do not be so dismayed, people. Watch an episode of How I Met Your Mother (Seasons 1 & 2 available on DVD, yay!) and see the less-Apatowish side of Jason Segel. My recommendation would be "Slap Bet" or "Goodbye, Fiyero".
PS: I can't wait to see the puppet Dracula scene in "Sarah Marshall"!