John K. wrote a great post yesterday about "what makes Funny Puppets". I love his take on the charm of vintage puppets and maybe there's something to his claim that The Muppets inadvertantly ruined puppetry by being so successful that almost everyone decided to copy their style without understanding the elements of their work that made them so successful in the first place (be sure to read the comments underneath the post for some lively discussion).
19/08/08 Update: Just to clarify (since I got a few emails from upset readers), I don't really think that the Muppets ruined puppetry. The Muppets have inspired a lot of puppetry over the years - some good and a lot of it bad - which just goes to show how difficult it is to do what they do well.