Just want to say something else.
The Muppets are REAL. They exist in our world. They are real human beings (actually, frogs, chickehs, bears..and a whatever) who have feelings, like a real human.
You can actually meet (example) Gonzo in person. I remember they talked about something similar on the MuppetCast (Steve Whitmire episode part 1).
{quote} "You can go to Walt Disney World, for example, and meet Cinderella, and tell her a secret, but when you come back the next day, Cinderella might be there, but she won't remember what you told her. It might be a different person in a Cinderella costume. If you tell something to Gonzo, and come back two years later, Gonzo will remember you, and so will Dave Goelz. Gonzo is nothing without Dave puppeteering him, without Dave, Gonzo doesn't exist anymore."
Have you ever met a CGI character? (I didn't think so, and no one ever did, not real, not a possibility.) But I know people, who have met real Muppets! With a CGI character, maybe you can meet the guy who provide the voice, but it wouldn't mean much anymore. These puppeteers bring these characters to life, voice actors, don't. That's the work of a big group of animators.
Sure, CGI is cool. No denying that TED looks really good. But the magic of The Muppets would be lost forever if they were tranfered to CGI.